the findings are published in today ' s issue of nature. " this calcium transporter really is an important key to understanding how the heart is regulated, " said dr. donald hilgemann, professor of physiology and senior author of the study. " at every beat, calcium in heart cells increases. and it ' s calcium that is the messenger to the heart to get it to contract. " we knew for a long time that ncx1 brings calcium into and out of heart cells by exchanging it for sodium. and in doing so it generates important electrical currents in the heart. the surprise is that this transporter dances more than just that old waltz from vienna. it knows salsa! " the research reveals two new modes of operation of ncx1. first, the membrane protein can move sodium into heart cells without moving calcium out. this mode generates an electrical current independent of calcium transport that contributes to excitation of the heart. the second mode is to move calcium into heart cells without generating any electrical current. this mode, dr. hilgemann said, may determine the calcium that remains in heart cells after each beat and thereby determines the strength of cardiac contraction over many beats. using so - called " giant membrane patch " techniques together with highly sensitive ion detection techniques, both developed and implemented by dr. hilgemann, ut southwestern researchers were able to determine precisely how ncx1 works as an ion exchanger, how many calcium and sodium ions move across the membrane, when they are exchanged, and, surprisingly, when they move together. " transporters move ions across membranes by grabbing hold of them and transferring the energy of one type of ion to another type, just one contact : amy shields ut southwestern medical center


expect a dramatic change, " he said. " these students started relatively empathetic and became more empathetic. " among the changes, participants in the simulation shifted their opinions about whether people who are poor attempt to get out of poverty ; whether they attempt to save money ; and whether they ' d rather work than be on welfare. in addition, their views on whether the poor have equal access to health care and whether the government does enough to help those who are poor, also shifted. they gained a better understanding of the fact that there are more children than adults living in poverty. in looking at the reflective papers the students wrote a week after the simulation, the researchers found that 65 of the 75 students who wrote papers described themselves as having gained greater insights into the lives of the poor as a result of the simulation. among the remaining students, seven reported no change in their opinions ( in some cases, they stated they already were empathetic to the poor ) and the responses of three students were ambiguous. " i began to understand and realize that it ' s not always a person ' s fault for being in a poverty - stricken lifestyle, " wrote one student. " just sitting in an environment of failure makes your own drive to succeed that much harder. " another student was surprised by the difficulty of assessing social services : " i knew very little about tanf ( temporary assistance for needy families ). i cannot imagine that everyone that is in need of help knows all about the programs available to them. " one finding the authors hadn ' t anticipated, based on previous studies that examined empathy, was the stress the participants felt as they inhabited the roles of those living in poverty. " the stress... was brought on entirely by my family ' s financial insecurity, " a student said. " i had little time to do anything other than go to work, run errands and pay the bills ; i barely saw my children or husband and never had the chance to relax. " " getting groceries, applying for tanf and food stamps and going to the quickcash all took so long to get accomplished, " wrote another. " i think that many people in poverty would feel like they were on a treadmill, not really getting anywhere. " " much of what students learn in the family resources class emphasizes the breadth of resources that are available, including time, space, and family and community support, in addition to the monetary and material goods we frequently think of, " nickols said. " part of what this simulation demonstrates is


uga researcher developing new vaccine to fight resurging mumps virus june 13, 2012print athens, ga. - mumps may seem like a disease of a bygone era to many people in the u. s. who, thanks to immunization programs, have been spared the fever, aches and characteristic swollen jawline of the once common viral infection. biao he, a university of georgia professor of infectious diseases and a georgia research alliance distinguished investigator in the college of veterinary medicine, worries that a new strain of the virus is spreading, and it could lead to the widespread reintroduction of mumps. now, thanks in part a $ 1. 8 million grant from the national institutes of health, he and his team are working on a new vaccine to stop it. although not typically a life - threatening disease, mumps can lead to serious health problems such as viral meningitis, hearing loss and pancreatitis ; and it can cause miscarriage during early pregnancy. vaccinations diminished the number of cases dramatically, and at one point it appeared that the u. s. was on pace to eradicate the disease. but two large outbreaks of the virus in 2006 and 2010 involving thousands of confirmed cases in the midwest and northeast put the hope of eradication on hold. he is concerned that the current vaccine, which has been in use since 1967, may be showing signs of weakness. " the virus is always evolving and mutating, and new viruses will emerge, " he said. " it ' s only a matter of time until the old vaccine we have doesn ' t work. " the current vaccine is commonly called the jeryl lynn strain and is named after the daughter of inventor maurice hilleman. it is based on a specific genotype of the mumps virus called genotype a. however, the 2006 and 2010 mumps outbreaks were caused by another strain, genotype g. even more troubling is that most of the people who contracted mumps during the 2006 and 2010 outbreaks had received the recommended two - dose vaccination in their early childhood, meaning that the virus was spreading even among the vaccinated population. " the question is : with this new genotype virus emerging in the vaccinated population, what do you do about it? " he said. some have suggested administering a third jeryl lynn vaccine to boost immunity later in life, but it is unclear if that approach would be successful. he suggests that modern scientific techniques have made the creation of some vaccines


you do about it? " he said. some have suggested administering a third jeryl lynn vaccine to boost immunity later in life, but it is unclear if that approach would be successful. he suggests that modern scientific techniques have made the creation of some vaccines much easier, so producing a new mumps vaccine may be the most effective method of controlling the emerging threat. " in the past few years, we have taken advantage of genetic engineering, and my lab is particularly good at engineering viruses, " he said. " we can take a virus, look at its genetic sequence, take bits and pieces away and generate a new virus with less virulence that will work as a vaccine. " before the advent of genetic engineering, the process of creating a vaccine could be intensely laborious, as researchers would have to pass the virus through many generations of reproduction until they found a naturally occurring weakened virus. this process can take long periods of time, and there is little guarantee that the weakened virus will work as a vaccine. genetic engineering allows he ' s lab to produce an effective and safe vaccine much more quickly. vaccine safety became a topic of much discussion after british medical researcher andrew wakefield suggested that there was a link between the measles, mumps and rubella vaccine and autism. however, his claims were found to be fraudulent, and wakefield was barred from practicing medicine in the united kingdom. much of the fallout from the wakefield case remains, and some are still hesitant to have their children vaccinated, but he is insistent that administering vaccines to children is the safe and responsible thing to do. " the no. 1 issue for us in making a pediatric vaccine is safety, " he said. " so far our testing suggests we are on the right track. " once he and his laboratory have devised a safe, reliable method to create vaccines for genotype g, they can apply that knowledge to rapidly produce vaccines for the other 12 mumps genotypes currently circulating in populations throughout the world. health professionals were able to contain the outbreaks of 2006 and 2010, but he thinks that the large global population and ease with which people move from one location to another make humankind vulnerable to rapid disease spread. " it ' s almost like a small fire ; if it stays small, we can put it out, " he said. " but if conditions are right, and the wind begins to blow, the fire can take over. " research reported in this publication was supported by the national institutes of health under award number 1r01ai097368 -


cool crop circles last year, quite a complex and elaborate 100ft diameter circle appeared overnight in a field of oil seed rape near silbury hill, wiltshire cool crop circles unseasonably warm and wet spring weather has seen many summer flowers appearing earlier than usual, and, surprisingly for so early in the year as things normally go, has sparked the crop circle creationists into early action. last year, quite a complex and elaborate 100ft diameter circle appeared overnight in a field of oil seed rape near silbury hill, wiltshire, causing a bit of a stir, a fabulous floral creation of six interlocking ' petal ' like crescent shapes, the very first proper design of the season, according to expert lucy pringle. from petersfield in hampshire, lucy is a founder member of the centre for crop circle studies, widely known as an international authority on crop circles, having carried out research over several years into both physiological and psychological effects on those visiting such installations. her research has revealed that there are measurable changes to hormone levels and brain activity in humans after coming into the vicinity of these creations, which have in past years included triangles, birds, complex 3 - d geometric shapes, as well as ahidden mathematical codes, such as that found in 2008 near wroughton, wiltshire, thought to represent the first ten digits of the pi number. a massive crop circle 200ft across appeared overnight close to the age - old topic of conversation amongst scholars, stonehenge, long thought of as a hot spot for this bizarre practice, being the tallest prehistoric man - made mound in europe, iand an obvious focal point. whilst there are indeed those who believe crop circles an entirely man - made phenomenon, others believe them caused by the magnetic field of the planet, while those out on the periphery think them the work of extra - terrestrial being trying to communicate. exactly how crop circles are created is still a mystery in many ways, and enthusiasts argue that not enough night hours exist in summer to allow humans to complete the complex creations. whatever the truth is, the rash of environmental art, of sorts, which gives farmers cause to feel frustration at the mindless destruction of good crop plants, is likely to always be a feature of the summer months. whether or not somebody ever manages to establish just how they are created remains to be seen, but i personally would not bet against the e. t. idea. the truth, as they say, is out there.


as part of the wrap - up for this course, we ’ re looking back at some of the first things we wrote in june ( introduction to webtools, setting the stage, and guiding principles for tech use in the classroom ). i don ’ t know that my thinking / philosophy on using technology has changed dramatically in the past two and a half months. i was on - board with tech use in the classroom with the goal of improved learning and connection, and i was excited to try out some new tools and learn from a new and diverse group of educators. i still am. i do have a clearer picture of some specific tools that i ’ d like to implement this year in my classes, and i am happy to have made many new connections in my continually - expanding pln. what has changed for me is a renewed focus on the idea that the best web tools allow us to do something completely new. i find myself coming back to three points from jeff utecht ’ s article “ evaluating technology use in the classroom ” : - does the technology allow students to learn from people they never would have been able to without it? - does the technology allow students to interact with information in a way that is meaningful and could not have happened otherwise? - does the technology allow students to create and share their knowledge with an audience they never would have had access to without technology? [ my emphasis ] i ’ ve been focused primarily on the second bullet point ( which isn ’ t horrible ). if that ’ s all we do with new technology, it still represents movement in the right direction. i ’ ve made some progress on the third point ( through student blogging ), but i don ’ t think i ’ ve tapped into the full potential there. my students were very excited to keep track of their blog ’ s page views counter, and they broadened their readership by putting their new biology blog posts up on facebook. ( which, come to think of it, is actually a pretty significant step. i wonder if they were sharing any of their history essays, spanish translations, or math problem sets on fb? ) but i want to try to find some ways to have them interact with people outside of our classroom, outside of our state and country, if possible. that ’ s a new goal of mine for the year. lastly, we should recognize that we ’ re going to ask our students to jump into this whole using tech in the classroom in new ways thing along with us. they ’ ll get their own crash courses in web


first, the truth is that no one really knows why some products succeed and others don ’ t. as the purchasing of goods in the market done by multiple individuals whose decisions are often personal and multi - factorial, direct observation and dissection of behavior is nearly impossible. there are some theories, though ( largely from van den bulte, 2007 ). so that i don ’ t forget, and purely for my own benefit, here ’ s a breakdown : 1. people who buy early are different from those who buy late. for example, the people who sit in the cold waiting to buy the new iphone on the day it is released are vastly different from those who wait until the price drops 6 months later. it ’ s hard to tell who ’ s smarter. me, i like heat. ( see rogers, 2003. ) 2. there are market leaders that other people like to follow. people buy products because they want to imitate others, who might mostly be those who pick up on fads early, i. e. there are “ innovators ” and “ imitators. ” people who bought to iphone 1 ( what did that look like? ) early showed it to their friends, who bought one, too. ( see bass, 1969 ) 3. people buy products autonomously, because of influence from above, or because of peer influence. some people buy stuff caring little for anyone else. some people buy stuff because an authority said it was a good idea. some people buy stuff because their friends do. ( see riesman, 1950 and schor, 1998 ) 4. purchase decisions depend on social status. some people buy stuff because they want to emulate those higher on the social ladder than they are. similarly, those on top buy new stuff because they don ’ t want to fall behind or be unseated as a high profile consumer. some people tend to want to buy slightly more car than they can afford, so that they can feel more like those with more money than they have. the stratified nature of society, thus, perpetuates a system of striving to consume more beyond one ’ s means. this desire is, of course, endless. ( see simmel 1971 and burt 1987 ) 5. marketing is a two step process. ads are only effective at influencing behavior of leaders, who, in turn influence their followers. i call this the “ economist effect. ” only a few sad people ( such as myself ) read the british magazine, the economist. when


ai and society 9 ( 1 ) : 29 - 42 ( 1995 ) | abstract | | this paper first illustrates what kind of ethical issues arise from the new information, communication and automation technology. it then argues that we may embrace the popular idea that technology is ethically neutral or even ambivalent without having to close our eyes to those issues and in fact, that the ethical neutrality of technology makes them all the more urgent. finally, it suggests that the widely ignored fact of normal responsible behaviour offers a new and fruitful starting point for any future thinking about such issues | | keywords | | no keywords specified ( fix it ) | | through your library | | configure | similar books and articles thomas w. cooper ( 1998 ). new technology effects inventory : forty leading ethical issues. journal of mass media ethics 13 ( 2 ) : 71 – 92. william p. cordeiro ( 1997 ). suggested management responses to ethical issues raised by technological change. journal of business ethics 16 ( 12 - 13 ) : 1393 - 1400. robin s. dillon ( 2010 ). respect for persons, identity, and information technology. ethics and information technology 12 ( 1 ). patrick feng ( 2000 ). rethinking technology, revitalizing ethics : overcoming barriers to ethical design. science and engineering ethics 6 ( 2 ) : 207 - 220. walter maner ( 1996 ). unique ethical problems in information technology. science and engineering ethics 2 ( 2 ). david wright ( 2011 ). a framework for the ethical impact assessment of information technology. ethics and information technology 13 ( 3 ) : 199 - 226. richard de george ( 2006 ). information technology, globalization and ethics. ethics and information technology 8 ( 1 ). bernd stahl, richard heersmink, philippe goujon, catherine flick, jeroen van den hoven, kutoma wakunuma, veikko ikonen & michael rader ( 2010 ). issues, concepts and methods relating to the identification of the ethics of emerging icts. communications of the iima 10 ( 1 ) : 33 - 43. michael d. myers & leigh miller ( 1996 ). ethical dilemmas in the use of information technology : an aristotelian perspective. ethics and behavior 6 ( 2 ) : 153 – 160. chris gastmans ( ed. ) ( 2002 ). between technology and humanity : the impact of technology on health care ethics. leuven university press. nabila boukef charki ( forthcoming )


( 2 ) : 153 – 160. chris gastmans ( ed. ) ( 2002 ). between technology and humanity : the impact of technology on health care ethics. leuven university press. nabila boukef charki ( forthcoming ). toward an ethical understanding of the controversial technology of online reverse auctions. journal of business ethics. bernd carsten stahl, richard heersmink, philippe goujon, catherine flick, jeroen van den hoven, kutoma wakunuma, veikko ikonen & michael rader ( 2010 ). identifying the ethics of emerging information and communication technologies : an essay on issues, concepts and method. international journal of technoethics 1 ( 4 ) : 20 - 38. iordanis kavathatzopoulos ( 2003 ). the use of information and communication technology in the training for ethical competence in business. journal of business ethics 48 ( 1 ) : 43 - 51. mike cooley ( 1995 ). the myth of the moral neutrality of technology. ai and society 9 ( 1 ) : 10 - 17. matteo turilli, antonino vaccaro & mariarosaria taddeo ( 2012 ). internet neutrality : ethical issues in the internet environment. philosophy and technology 25 ( 2 ) : 133 - 151. sorry, there are not enough data points to plot this chart. added to index2010 - 08 - 30 total downloads1 ( # 277, 212 of 556, 837 ) recent downloads ( 6 months ) 0 how can i increase my downloads?


after higgs boson, scientists prepare for next quantum leapfebruary 13th, 2013 in physics / general physics a graphic distributed on july 4, 2012 by cern in geneva shows a representation of traces of a proton - proton collision measured in the search for the higgs boson. seven months after its scientists made a landmark discovery that may explain the mysteries of mass, europe ' s top physics lab will take a break from smashing invisible particles to recharge for the next leap into the unknown. seven months after its scientists made a landmark discovery that may explain the mysteries of mass, europe ' s top physics lab will take a break from smashing invisible particles to recharge for the next leap into the unknown. from thursday, the cutting - edge facilities at the european organisation for nuclear research ( cern ) will begin winding down, then go offline on saturday for an 18 - month upgrade. a vast underground lab straddling the border between france and switzerland, cern ' s large hadron collider ( lhc ) was the scene of an extraordinary discovery announced in july 2012. its scientists said they were 99. 9 percent certain they had found the elusive higgs boson, an invisible particle without which, theorists say, humans and all the other joined - up atoms in the universe would not exist. the upgrade will boost the lhc ' s energy capacity, essential for cern to confirm definitively that its boson is the higgs, and allow it to probe new dimensions such as supersymmetry and dark matter. " the aim is to open the discovery domain, " said frederick bordry, head of cern ' s technology department. " we have what we think is the higgs, and now we have all the theories about supersymmetry and so on. we need to increase the energy to look at more physics. it ' s about going into terra incognita ( unknown territory ), " he told afp. theorised back in 1964, the boson also known as the god particle carries the name of a british physicist, peter higgs. he calculated that a field of bosons could explain a nagging anomaly : why do some particles have mass while others, such as light, have none? that question was a gaping hole in the standard model of particle physics, a conceptual framework for understanding the nuts - and - bolts of the cosmos. one idea is that the higgs was born when the new universe cooled after the big bang some 14 billion years ago. it


gaping hole in the standard model of particle physics, a conceptual framework for understanding the nuts - and - bolts of the cosmos. one idea is that the higgs was born when the new universe cooled after the big bang some 14 billion years ago. it is believed to act like a fork dipped in honey and held up in dusty air. most of the dust particles interact with the honey, acquiring some of its mass to varying degrees, but a few slip through and do not acquire any. with mass comes gravity — and its pulling power brings particles together. supersymmetry, meanwhile, is the notion that there are novel particles which are the opposite number of each of the known particle actors in the standard model. this may, in turn, explain the existence of dark matter — a hypothetical construct that can only be perceived indirectly via its gravitational pull, yet is thought to make up around 25 percent of the universe. at a cost of 6. 03 billion swiss francs ( 4. 9 billion euros, $ 6. 56 billion dollars ), the lhc was constructed in a 26. 6 - kilometre ( 16. 5 - mile ) circular tunnel originally occupied by its predecessor, the large electron positron ( lep ). that had run in cycles of about seven months followed by a five - month shutdown, but the lhc, opened in 2008, has been pushed well beyond. " we ' ve had full operations for three years, 2010, 2011 and 2012, " said bordry. " initially we thought we ' d have the long shutdown in 2012, but in 2011, with some good results and with the perspective of discovering the boson, we pushed the long shutdown back by a year. but we said that in 2013 we must do it. " unlike the lep, which was used to accelerate electrons or positrons, the lhc crashes together protons, which are part of the hadron family. " the game is about smashing the particles together to transform this energy into mass. with high energy, they are transformed into new particles and we observe these new particles and try to understand things, " bordry explained. " it ' s about recreating the first microsecond of the universe, the big bang. we are reproducing in a lab the conditions we had at the start of the big bang. " over the past three years, cern has slammed protons together more than six million billion times. five billion collisions yielded results deemed worthy of further research and data from only


in a lab the conditions we had at the start of the big bang. " over the past three years, cern has slammed protons together more than six million billion times. five billion collisions yielded results deemed worthy of further research and data from only 400 threw up data that paved the road to the higgs boson. despite the shutdown, cern ' s researchers won ' t be taking a breather, as they must trawl through a vast mound of data. " i think a year from now, we ' ll have more information on the data accumulated over the past three years, " said bordry. " maybe the conclusion will be that we need more data! " last year, the lhc achieved a collision energy level of eight teraelectron volts, an energy measure used in particle physics — up from seven in 2011. after it comes back online in 2015, the goal is to take that level to 13 or even 14, with the lhc expected to run for three or four years before another shutdown. the net cost of the upgrade is expected to be up to 50 million swiss francs. cern ' s member states are european, but the prestigious organisation has global reach. india, japan, russia and the united states participate as observers. ( c ) 2013 afp " after higgs boson, scientists prepare for next quantum leap. " february 13th, 2013. http : / / phys. org / news / 2013 - 02 - higgs - boson - scientists - quantum. html


the dialogue. according to him, the dialectical discussion on the one and the many ( ta alla ) reveals the first divine principles of all things. with the exception of the commentary on the cratylus, of which only a selection of notes from the original commentary is preserved, the exegetical works of proclus have a clear structure. they divide the platonic text in different lemmata or cited passages, discussing first the doctrine exposed in the particular section ( pragmata, later called theoria ), next commenting on the formulation of the argument ( called lexis ) [ see festugiere 1963 ]. whereas modern scholars usually accept a development in plato ' s thought and distinguish between an early, middle, and late plato, the neoplatonists take the platonic corpus as the expression of a divinely inspired and unitary philosophical doctrine. this enables them to connect different platonic dialogues into one system and to see numerous cross - references within the platonic oeuvre. what may seem to be contradictions between statements made in different dialogues, can be explained by different pedagogical contexts, some dialogues being rather maieutic than expository, some elenctic of the sophistic pseudo - science, some offering a dialectical training to young students. a neoplatonic commentary offers much more than a faithful interpretation of an authoritative text of plato. plato ' s text gives the commentator an opportunity to develop his own views on the most fundamental philosophical questions, the first principles, the idea of the good, the doctrine of the forms, the soul and its faculties, nature, etc. as was said, the two culminating dialogues, the timaeus and the parmenides, offer together a comprehensive view of the whole of platonic philosophy. since the whole philosophy is divided into the study of intelligibles and the study of things within the cosmos – and quite rightly so, as the cosmos too is twofold, the intelligible and the sensible, as timaeus himself will say in what follows ( timaeus 30c ) – the parmenides comprehends the study ( pragmateia ) of the intelligibles and the timaeus the study of things within the cosmos. for the former teaches us all the divine orders and the latter all processions of things within the cosmos. ( in tim. i 12. 30 – 13. 7 ) the interpretation of the parmenides thus prepares the way for the platonic theology, offering the systematic structure for a


divine orders and the latter all processions of things within the cosmos. ( in tim. i 12. 30 – 13. 7 ) the interpretation of the parmenides thus prepares the way for the platonic theology, offering the systematic structure for a scientific demonstration of the procession of all the orders of gods from the first principle. as proclus explains at theol. plat. i 2, p. 9. 8 – 19, the platonic theology falls into three parts ( after a long methodological introduction ). the first part ( theol. plat. i 13 – 29 ) is an investigation into the common notions ( koinai ennoiai ) of the gods as we find them in plato ' s dialogues : it is a treatise on the divine names and attributes. the second part ( theol. plat. ii – vi ), which is incomplete, unfolds in a systematic way the procession of the divine hierarchies, from the one, that is the first god, to the ‘ higher kinds, ’ i. e., angels, daimones, and heroes, while the third part, which is altogether missing, was supposed to deal with the individual hypercosmic and encosmic gods. before presenting his own views, proclus usually critically evaluates the opinions and interpretations of his predecessors. in this respect, his commentaries are a rich and indispensible source for the history of middle and neo - platonism. thus, in his commentary on the timaeus proclus reports and criticizes the views of atticus, numenius, longinus, plotinus, porphyry, iamblichus, theodorus of asine and many others, ending usually in full agreement with the explanation of his master syrianus. besides, in explaining plato ' s text, proclus frequently seeks confirmation of his exegesis in the chaldaean oracles or the orphic tradition. as syrianus ( see helmig 2009 ), proclus is often very critical of aristotle and refutes his criticism of plato ' s views. he is certainly not an advocate of the “ harmony of plato and aristotle, ” which became the leading principle of the alexandrian commentaries ( of ammonius and simplicius ). proclus notes significant differences between the two philosophers in epistemology ( theory of abstraction vs. learning as recollection ), metaphysics ( first principle, theory of forms, theory of universals ), physics


simplicius ). proclus notes significant differences between the two philosophers in epistemology ( theory of abstraction vs. learning as recollection ), metaphysics ( first principle, theory of forms, theory of universals ), physics ( plato ' s timaeus vs. aristotle ' s physics ), political philosophy ( aristotle ' s criticism of plato ' s republic ), and language ( cratylus vs. de interpretatione ). according to proclus, plato is not only far superior to aristotle in his theology ( as only plato ascended beyond the intellect to posit the one as the ineffable principle of all things ), but in all other philosophical disciplines, where we owe to him all important discoveries. whereas the peripatetics were accustomed to defend the superiority of aristotle over plato with reference to his impressive physical project, proclus considers the latter as inferior to the great achievement of plato in the timaeus ( see steel 2003 ). aristotle ' s natural philosophy is the work of a zealous admirer, a disciple who tried to be better than the master : it seems to me that the excellent aristotle emulated the teaching of plato as far as possible when he structured the whole investigation about nature. ( in tim. i 6. 21 – 24 ) following plato, aristotle explains in his physics the general principles of natural things : form, matter, nature, the essence and principles of movement, time and place ; again taking inspiration from the timaeus, he studies in other works the specific principles of the distinct regions of the physical world, thus in the de caelo the celestial and the sublunary realm, and in on generation and corruption and in meteorologica the sublunary realm. in this domain, it cannot be denied, aristotle did much more than his master. according to proclus, however, he developed the subject ‘ beyond what is needed ’. the same remark must be made about aristotle ' s extensive zoological research. whereas plato limited himself in the timaeus to an analysis of the fundamental principles of all living organisms, aristotle gave most of his attention to the material components of animals and scarcely, and only in few cases, did he consider the organism from the perspective of the form. plato, on the contrary, when explaining the physical world, never got lost in a detailed examination. when trying to determine proclus ' profile as a philosopher, one has to keep in mind that platonists were not keen on introducing new elements into the plato


the contrary, when explaining the physical world, never got lost in a detailed examination. when trying to determine proclus ' profile as a philosopher, one has to keep in mind that platonists were not keen on introducing new elements into the platonic doctrine. they despised innovation ( kainotomia ). yet it cannot be denied that neoplatonic philosophy differs considerably from what we read in plato ' s dialogues. there is also overwhelming evidence for continual discussions in the school on the right interpretation of plato or on certain doctrinal points ( such as the transcendence of the one, or the question whether the soul wholly descended from the intelligible world ). in order to evaluate proclus ' originality, one ought to compare his views with those of the neoplatonists before him, such as plotinus, porphyry, iamblichus, and syrianus. only with regard to plotinus is this possible to a great extent, because we still have the full corpus of plotinus ' writings. proclus certainly admired the first ‘ founder ’ of the new platonism and even devoted a commentary to the enneads, of which, alas, we have only some fragments. he shared plotinus ' views on the three principal hypostases the one, the intellect and the soul, and often uses language inspired by his reading of plotinus, as in his description of the union of the soul with the ineffable one. yet on many points, he is very critical of plotinus, pointing to contradictions, rejecting provocative views such as the thesis that one is cause of itself ( causa sui ), the doctrine of the undescended soul, or the identification of evil with matter. another radical difference from plotinus ( and porphyry ) is the importance attributed to theurgy for the salvation of the soul and the authority of chaldaean oracles. as said before, it is very difficult to mark off proclus ' originality with regard to his teacher syrianus, the only predecessor he never criticizes. of the literary production of the latter, we have only his commentary on aristotle ' s metaphysics. it is possible that most of syrianus ' courses on plato never were published, but were continued and further worked out by proclus himself. we have, however, the commentary on the phaedrus by hermeias, who was sitting together with proclus, in syrianus ' course. one gets the impression that


were continued and further worked out by proclus himself. we have, however, the commentary on the phaedrus by hermeias, who was sitting together with proclus, in syrianus ' course. one gets the impression that syrianus was very interested in orphic theogony, whereas for proclus the chaldaean oracles are more authoritative when developing a platonic theology. but here again, it is difficult to compare as we do not possess proclus ' own commentary. is proclus after all then not so original, but only an excellent teacher and wonderful systematizer of the new platonic doctrines which became dominant in the school since iamblichus on? we shall never know, and it is after all not so important when assessing the philosophical merits of his works. to praise proclus ' philosophical achievements, marinus devotes in life of proclus one chapter to the discussion of the doctrines we owe to him ( § 23 ). surprisingly, for all his admiration for the master, he can only enumerate a few innovative doctrines ; and they are of such a minor importance that we shall not even discuss them in this article. in late antiquity, aristotle ' s metaphysics was considered to be a theological work, because aristotle investigates in this treatise the first principles of all being. this discipline may be called theology, because the principles of beings and the first and most perfect causes of things are what is most of all divine. ( asclepius, in metaph. 4. 1 – 3 ) indeed, there is precedent for this in aristotle himself, for in metaphysics vi, 1, 1026a15ff, he classifies “ first philosophy, ” or metaphysics, as theology. proclus himself often uses the term ‘ theology ’ in this metaphysical sense for the study of the first ( ‘ divine ’ ) principles of all things. his elements of theology can in fact be considered an introduction to his metaphysics. the work is a concatenated demonstration of 217 propositions, which may be divided into two halves : the first 112 propositions establish the one, unity without any multiplicity, as the ultimate cause of reality and lay down basic metaphysical concepts / structures such as causality, participation, the relation of wholes to parts, infinity, and eternity. the second half deals with the three kinds of true causes within reality recognized by proclus : gods ( which he calls henads or “ unities, ” see below ), intellects


relation of wholes to parts, infinity, and eternity. the second half deals with the three kinds of true causes within reality recognized by proclus : gods ( which he calls henads or “ unities, ” see below ), intellects, and souls. this elaborate metaphysical framework makes it possible for proclus to develop a scientific theology, i. e., a demonstration of the procession and properties of the different classes of gods. in what follows we will only discuss some characteristic features of proclus ' metaphysics ( see further steel 2011 ). on the whole, proclus ’ doctrine of first principles is a further development of plotinus ' innovative interpretation of platonic philosophy. with plotinus, proclus recognizes three fundamental levels of reality called ‘ hypostases ’ ( or self - subsistent entities ) : one, intellect, and soul. however, following a concern of his predecessor iamblichus for greater precision in the relationship and distinction between the one and intellect, proclus distinguishes between the intelligible being ( to noeton — what is the object of intellectual intuition ) and the intellective ( to noeron — what is intelligizing ), and introduces between both, as an intermediary level, the noeton - noeron ( what is being intelligized and intelligizing ). these three ontological levels thus correspond to the triad of being, life, and intellect, which already play an important role in plotinus ' and porphyry ' s speculations about the procession or ‘ emanation ’ of the intelligible world from the one, without, however, being hypostasized. since zeller ( influenced by hegel ) the application of the triadic structure to reality has been seen as the characteristic feature of proclus ' system, but see dodds 19632, pp. xxii and 220, on possible sources of the doctrine. although the distinction of aspects of reality as distinct hupostases and the multiplication of triads might suggest a loss of plotinus ’ intuition of the unity of reality, it is important to stress that each part of the triad of being, life and intellect, mirrors within itself their triadic relationship. this redoubled triadic structure must be understood as expressing an intrinsic and essential relation between successive levels of being. the intimate relation between being, life, and intellect is the origin of the basic structure uniting all causes to their effects, namely the relation of immanence,


ones that are participated in by something, are connected by means of “ the triad of triads ” ( elem. theol. § 23 ), the universal nature of the form can be safeguarded. proclus, however, also applies this principle to explain the most difficult problem facing neoplatonic metaphysics, namely, how to understand the procession of the manifold from the one. how can the one be wholly without multiplicity, when it must somehow be the cause of any and all multiplicity? the one remains in itself absolutely unparticipated ; the many different beings proceeding from it participate in a series of participated henads or unities ( gods ). according to some scholars it was iamblichus who introduced this innovative doctrine, others attribute it to proclus ' teacher syrianus. even if the doctrine does not originate as such from iamblichus himself, the existence of the divine henads somehow follows from his law of mean terms. this law states that “ every producing cause brings into existence things like to itself before the unlike. “ ( elem. theol. § 28 ). thus there are no leaps in the chain of being, but everything is linked together by similar terms. the henads fulfill this function, for as participated unities they bridge the gap between the transcendent one and everything that comes after it. the doctrine of the henads can thus be seen as a way of integrating the traditional gods of greek polytheistic religion into the neoplatonic metaphysics of the one. a. auxiliary and true causes. from middle platonism onwards, various attempts were made to integrate the aristotelian doctrine of causes within the platonic philosophy ( see steel 2003 ). in plato ' s work, it was argued, one can find the four types of causality that aristotle distinguishes, to wit formal, material, efficient, final, and, besides, the paradigmatic cause, which aristotle wrongly rejected. this system of causes ( with the addition of the instrumental cause as a sixth ) became standard in later neoplatonism. in his commentary on the timaeus, proclus observes that aristotle never rises to the proper level of causality. for the four causes, as aristotle understands them, can only be applied to the explanation of processes in the sublunary world. in the platonic view, however, the material and formal causes are only subservient or instrumental causes. those causes are in fact immanent in their effects and consti


applied to the explanation of processes in the sublunary world. in the platonic view, however, the material and formal causes are only subservient or instrumental causes. those causes are in fact immanent in their effects and constitutive elements of the thing they produce. as proclus asserts in prop. 75 of the elements of theology, “ that which exists in the effect is not so much a cause as an auxiliary cause ( sunaition ) or an instrument of the producer. ” causes in the proper sense must act upon their effects from outside, while transcending them. for a proper understanding of what the true causes are of all things, proclus argues, one must follow plato, who lifts us up to the level of the transcendent forms and makes us discover the creative causality of the demiurge and the finality of the good as the ultimate explanation of all aspirations. although aristotle also discusses efficient and final causes, he falls short of a true understanding of creative causality because he abandons the hypothesis of the forms. without the transcendent forms, there can be no explanation of the being of things, only an explanation of their movement and change. given aristotle ' s narrow understanding of nature, it must come as no surprise, proclus notices, that he admits of cases of ‘ spontaneous generation ’ in the sublunary realm, which again restricts the purport of efficient causality. moreover, because of his rejection of the demiurge ( and of the one ), aristotle is also forced to limit efficient causality to the sublunary realm. in fact, in his view there is no cause of existence of the celestial bodies or of the sensible world as a whole : they exist necessarily in all eternity. but, as proclus argues, such a position will force him to admit that the world has the capacity to constitute itself, which is absurd ( see below ). the neoplatonic concept of causality is therefore quite different from that of the peripatetics, even if both share the same terminology, such as final or efficient cause. aristotle ' s causes are primarily intended to explain how things move and change, come to be and cease to be, but also offer to explain what given things are. for the neoplatonists, generalizing a principle formulated in the philebus — “ that everything that comes to be comes to be through a cause ” ( 26e, cf. tim. 28a ) — causality


given things are. for the neoplatonists, generalizing a principle formulated in the philebus — “ that everything that comes to be comes to be through a cause ” ( 26e, cf. tim. 28a ) — causality is of much wider application than the explanation of change and motion, it is not only about what things are, but about what constitutes ( hupostatikos ) their being, and it can be, analogously, used to explain relations between all levels of being. thus we can say of the one that it is the cause of intellect, and of intellect that it is cause of soul. in the timaeus, however, the main interest is to understand what is the cause of the sensible world and all the cosmic beings : this is primarily the demiurge or creator of the world ( the one is not the ‘ creator ’ of intellect ). b. corporeal and incorporeal causes. according to the stoics only bodies and powers or qualities of bodies are capable of acting and being acted upon ( see steel 2002 ). the platonists often criticized the stoic view and pointed to what they thought were the many contradictions involved, in particular, in the materialistic explanation of psychic activities or dispositions such as virtues. they defended the opposite view : all forms of causality must ultimately be explained as emanating from incorporeal entities. proclus adopts plotinus ' view ( iv, 7 8a ), that only incorporeal beings can be causes in the strict sense, and includes it among the basic theorems of his metaphysics. see elem. theol. § 80 ( cf. theol. plat. i 14, p. 61. 23 – 62. 1 ) : every body has by its own nature the capacity to be acted upon, every incorporeal thing the capacity to act, the former being in itself inactive, the latter impassive ; but through association with the body, the incorporeal too is acted upon, just as bodies too can act because of the participation in incorporeal entities. in this proposition proclus first sets apart the corporeal and incorporeal as being active / impassible and passive / inactive respectively. however, the two realms are not absolutely separate from each other. the soul, which is an incorporeal substance, enters into association with the body and thus becomes itself, though only accidentally, subject to different passions


and passive / inactive respectively. however, the two realms are not absolutely separate from each other. the soul, which is an incorporeal substance, enters into association with the body and thus becomes itself, though only accidentally, subject to different passions. the body, on the contrary, may gain great profit from the association with the incorporeal. this is evident in the case of animated bodies, which owe all their vital activities to the presence of the soul in them. but also inanimate natural bodies acquire all capacities and powers from nature and its inherent logoi or organizing rational principles ( see steel 2002 ). c. the relation of cause to its effect. the relation between a cause and its effect is characterized by both similarity and dissimilarity. for every cause produces something that is similar to it, and every effect thus resembles its cause, though in a secondary and less perfect way. but in so far as the effect is really distinguished from its cause, it acquires its own characteristic form of being, which was not yet developed on the level of its cause. for this reason each thing can be said to exist in three manners ( elem. theol. § 65 ). first, it is in itself as expressing formally its own character ( kath ’ hyparxin ). second, it exists in a causal manner ( kat ’ aitian ) being anticipated in its cause. finally, it exists as being participated ( kata methexin ) by the next level of being, which is its effect. thus life is a property of a living organism as being participated by it. life characterizes the soul formally. life also exists qua form in the divine mind. finally, proclus stresses that the higher a cause, the more comprehensive it is, and the further its effects reach ( elem. theol. § 57 ). all things, including matter, which has in itself, apart from the forms existing in it, no ‘ being ’, participate in the one ; all beings participate in being ; all plants and animals participate in life ; all rational souls participate in intellect. proclus ' epistemology is firmly rooted in his theory of the soul. for proclus, souls as self - moving principles represent the lowest level of entities that are capable of reverting upon itself ( so called self - constituted beings [ authypostata ], see elem. theol. § 40 – 51 ). they are incorporeal, separable from bodies and ind


entities that are capable of reverting upon itself ( so called self - constituted beings [ authypostata ], see elem. theol. § 40 – 51 ). they are incorporeal, separable from bodies and indestructible / immortal ( elem. theol. § 186 – 7 ). yet, they are principles of life and of movement of bodies ( elem. theol. § 188 ). in accordance with proclus ' general metaphysical principles ( cf. above 3. 1 ), from the unparticipated soul - monad proceed different kinds of participated soul : divine souls, daemonic souls, human souls, souls of animals ). as with other platonists, proclus frequently discusses the vexed question as to why a soul would descend into a body at all ( ‘ fall of the soul ’ ) ( see dorrie / baltes ( 2002. 2 ) 163 – 218 ). moreover, the neoplatonist distinguishes between altogether three so - called vehicles ( ochemata ) of the soul. the rational soul is permanently housed in the luminous vehicle, while the non - rational soul is located in the pneumatic vehicle. by being incarnated in a human body, soul, or rather, the vegetative soul attains thus a ( third ) ‘ shell - like ’ vehicle. the theory of the different vehicles or the psychic ‘ astral body, ’ familiar nowadays from modern theosophic theories, fulfils several crucial functions in neoplatonic psychology : it explains ( a ) how an incorporeal soul can be linked to a body, ( b ) how souls can move in space, ( c ) how souls can be punished after death ( cf. plato ' s myths ), ( d ) where certain faculties of the soul such as imagination are located. proclus distinguishes between two kinds of vehicles, one mortal and the other immortal ( in tim. iii 236. 31 ff. and elem. theol. § 207 – 210 ). proclus also adheres to the platonic theory of transmigration, but argues that human souls never enter animal bodies as their constitutive forms. for only animal souls can be organizing principles of animal bodies. if some rational souls are ‘ degraded ’ in the next life and forced to live in an animal body because of their misdemeanour in this life, they are only ‘ relationally ’ ( schesei ) present to this


animal bodies. if some rational souls are ‘ degraded ’ in the next life and forced to live in an animal body because of their misdemeanour in this life, they are only ‘ relationally ’ ( schesei ) present to this animal body. proclus distinguishes between the following faculties of soul : sense perception, imagination ( phantasia ), opinion, discursive thought, and intellection. while sense perception and imagination belong to the non - rational soul, opinion forms the lowest level of rationality. the aim of epistemological ascent is to free oneself eventually from the lower psychic faculties, including the lower rational ones, in order to enjoy a state of pure contemplation. as with many other platonists, proclus ' epistemology is based on a theory of innate knowledge ( in accordance with the platonic dictum that ‘ all learning is recollection [ anamnesis ] ’ ). proclus refers to the innate contents of the soul as its reason - principles ( logoi ) or forms ( eide ). these innate reason - principles constitute the essence of soul. that is why they are called ‘ essential reason - principles ’ ( logoi ousiodeis ) ( steel 1997 ). the traditional translation reason - principles was chosen on purpose, because on an ontological level these same logoi serve as principles of all things. they are extended or unfolded images of the forms that exist in intellect ; and by means of them the world - soul with the assistance of nature brings forth everything. in other words, the psychic logoi are instantiations of platonic forms on the level of soul as are the logoi in nature and the forms immanent in matter. according to the fundamental neoplatonic axiom panta en pasin ( ‘ all things are in all things ’ ), forms exist on all levels of reality. but the logoi in soul also offer the principles of all knowledge and are the starting points of demonstration. at in parm. iv 894. 3 – 18 ( ed. steel ) proclus argues that only with reference to these notions within the soul predication is possible ( see helmig 2008 ), since they are universal in the true sense of the word. on the other hand, both transcendent platonic forms and forms in matter are not taken to be universals proper by proclus. the former are rather intelligible particulars, as it were, and cannot be defined ( steel


. on the other hand, both transcendent platonic forms and forms in matter are not taken to be universals proper by proclus. the former are rather intelligible particulars, as it were, and cannot be defined ( steel 2004 ), while the latter are strictly speaking instantiated or individualised universals that are not shared by many particulars ( see helmig 2008, cf. above 3. 1 – 2 ). for this reason, it does not make much sense to talk about ‘ the problem of universals ’ in proclus. it is another crucial assumption of proclus ' epistemology that all souls share the same logoi ( elem. theol. § 194 – 195 ). in terms of concept - formation this entails that psychic concepts, once they are grasped correctly, are universal, objective, and shareable ( see helmig 2011 ). moreover, if all souls share the same logoi, and these logoi are the principles of reality ( see above ), then by grasping the logoi souls come to know the true principles or causes of reality. already aristotle had written that to know something signifies to know its cause ( met. a 3, 983a25 – 26 and an. post. i 2, 71b9 – 12 ). in his commentary on plato ' s timaeus, proclus introduces an interesting distinction. taking his start from the problem of how we can recognise certain objects, he considers the example of an apple. the different senses tell us that there is something sweet, red, even, with a nice smell. and while common sense ( koine aisthesis ) can distinguish the different impressions of the special senses, only opinion ( doxa ) is capable of saying that the object there on the table is an apple. doxa is able to do this, because it has access to the innate logoi of the soul. however, as proclus explains ( in tim. i 248. 11 ff. ), opinion only knows the ‘ that ’ ( hoti ), that is, it can recognize objects. discursive thought ( dianoia ), on the other hand, also knows the ‘ why ’ ( dihoti ), that is, the causes of something. this distinction can also be rephrased in terms of concepts, implying a distinction between factual concepts that allow us to identify or recognise certain objects, and concepts that fulfil an explanatory role. on the whole, procl


something. this distinction can also be rephrased in terms of concepts, implying a distinction between factual concepts that allow us to identify or recognise certain objects, and concepts that fulfil an explanatory role. on the whole, proclus ' reading and systematisation of plato ' s doctrine of learning as recollection makes platonic recollection not only concerned with higher learning, since already on the level of object recognition we employ concepts that originate from the innate logoi of the soul ( helmig 2011 ). proclus argues at length that the human soul has to contain innate knowledge. therefore, one should not consider it an empty writing tablet, as aristotle does ( aristotle, de anima iii 4 ). he is wrong in asserting that the soul contains all things potentially. according to proclus, the soul contains all things ( i. e., all logoi ) in actuality, though due to the ‘ shock of birth ’ it may seem as if the soul has fallen to potentiality. at in crat. § 61, proclus asserts that the soul does not resemble an empty writing tablet ( agraphon grammateion ) and does not possess all things in potentiality, but in act. in eucl. 16. 8 – 13 expresses the same idea : “ the soul is not a writing tablet void of logoi, but it is always written upon and always writing itself and being written on by the intellect. ” as with his philosophy of mathematics, proclus presents a detailed criticism of the view that universal concepts are derived from sensible objects ( by abstraction, induction, or collection ). in the fourth book of his commentary on plato ' s parmenides and in the two prologues of the commentary on euclid we find the most comprehensive criticism of abstractionism in antiquity ( see helmig 2010 and 2011 ). proclus devoted three entire books or ‘ monographs ’ ( monobiblia ) to problems of providence, fate, free choice, and evil. the first treatise ( ten problems concerning providence ) examines ten different problems on providence that were commonly discussed in the platonic school. for proclus providence ( pronoia ) is the beneficent activity of the first principle ( the ‘ source of goods ’ ) and the gods ( henads ), who have their existence before intellect ( pro - nou ). one of the problems discussed is the question of how divine foreknowledge and human free choice can be reconciled. for if god


’ ) and the gods ( henads ), who have their existence before intellect ( pro - nou ). one of the problems discussed is the question of how divine foreknowledge and human free choice can be reconciled. for if god knows not only past and present, but also future events, the outcome of future events is already pre - determined ( as god has a determinate knowledge of all things ), and hence there is no free choice for humans. proclus ' answer, which ultimately goes back to iamblichus, consists in applying the principle that the mode of knowledge is not conditioned by the object known but by the knower. in the case of gods, this entails that they know the contingent event in a non contingent manner, the mutable immutably. they have an undivided knowledge of things divided and a timeless knowledge of things temporal ( elem. theol. § 124, cf. de decem dub. § 6 – 8 ). proclus ' answer was later taken up by ammonius in his commentary on the de interpretatione ix and in boethius ' consolation of philosophy v 6 as well as in his commentary on the de interpretatione ix. the second treatise ( on providence fate and what depends on us ) replies to a letter of theodore, a former friend of proclus. in this letter theodore, an engineer, had defended with several arguments a radical determinism, thus entirely excluding free choice. before refuting theodore ' s arguments, proclus introduces some fundamental distinctions in order to solve the problems raised by his old friend. the first distinction is between providence and fate : providence is essentially a god, whereas fate is something divine, but not a god. this is because it depends upon providence and is as it were an image of it. ( de prov. § 14 ) the second distinction is that between two types of soul : the rational soul is separable from the body, the irrational resides in the body is inseparable from its substrate ; “ the latter depends in its being upon fate, the former upon providence ” ( de prov. § 15 ff. ). the third distinction concerns knowledge and truth : one type of knowledge exists in souls that are bound to the process of generation ; [ … ] another type is present in souls that have escaped from this place. ( de prov. § 3. 1 – 4. 3 ) these three distinctions taken together make it possible for proclus to ultimately reconcile providence, fate


generation ; [ … ] another type is present in souls that have escaped from this place. ( de prov. § 3. 1 – 4. 3 ) these three distinctions taken together make it possible for proclus to ultimately reconcile providence, fate, and free choice. in so far as we are rational agents and let ourselves being determined in our choices only by intelligible principles, we may transcend the determinism of fate to which we belong as corporeal beings. yet, our actions are integrated into the providential order, as we willingly obey the divine principles. the third treatise ( on the existence of evils ) asks why and how evil can exist if the world is governed by divine providence. proclus argues that evil does not have an existence of its own, but only a derivative or parasitic existence ( par - hypostasis, sc. on the good ) ( de mal. § 50 ). in order to exist in a proper sense, an effect must result from a cause which proceeds according to its nature towards a goal that is intended. [ … ] whenever an effect is produced that was not intended or is not related by nature or per se to the agent, it is said to exist besides ( para ) the intended effect, parasitically upon it, as it were. ( opsomer - steel 2003, 25 ) this is precisely the case with evils, which are shortcomings and mistakes. as a failure is never intended qua failure by an agent, but is an unfortunate by - effect of its action, so is evil qua evil never caused by a cause. therefore, proclus continues, it is better to call its mode of existence a parhupostasis, rather than a hupostasis, a term that belongs to those beings “ that proceed from causes towards a goal. ” parhupostasis or “ parasitic existence, ” on the contrary, is the mode of existence of “ beings that neither appear through causes in accordance with nature nor result in a definite end. ” evils are not the outcome of goal - directed processes, but happen per accidens, as incidental by - products which fall outside the intention of the agents. [ … ] therefore it is appropriate to call such generation a parasitic existence ( parhupostasis ), in that it is without end and unintended, uncaused in a way ( anaition pos ) and indefinite. ( de mal. § 50. 3 – 9, 29 – 31


parasitic existence ( parhupostasis ), in that it is without end and unintended, uncaused in a way ( anaition pos ) and indefinite. ( de mal. § 50. 3 – 9, 29 – 31, transl. by opsomer - steel 2003 ) dionysius the areopagite adopted proclus ' views on evil in his work on the divine names. thanks to this adaptation proclus ' doctrine of evil had an enormous influence on the later medieval discussions on evil both in byzantium and in the latin west and dominated the philosophical debates on evil up to the 19th century. a theological physics although proclus composed a short ( presumably early ) treatise where he summarises aristotle ' s theory of movement ( elements of physics ), he does not understand physics primarily as the study of movement and change of natural phenomena, but rather seeks to connect these phenomena to their intelligible and divine causes ( physics as a kind of theology, in tim. i 217. 25 ). in the preface to his commentary on plato ' s timaeus proclus sets out to prove why plato ' s physics, as developed in the timaeus, is superior to natural science in the aristotelian sense ( see steel 2003 ). in proclus ' view plato ' s timaeus not only offers a physiologia, a science of nature in its many aspects, but also presents an explanation of the whole of nature by paying due attention to its incorporeal, divine causes : the natural world proceeds from the demiurge as the expression of an ideal paradigm and aims at the ultimate good. therefore, plato ' s physio - logy is also a sort of theo - logy : the purpose of timaeus will be to consider the universe, insofar as it is produced by the gods. in fact, one may consider the world from different perspectives : insofar as it is corporeal or insofar as it participates in souls, both particular and universal, or insofar as it is endowed with intellect. but timaeus will examine the nature of the universe not only along all those aspects, but in particular insofar as it proceeds from the demiurge. in that respect the physiology seems also to be a sort of theology, since also natural things have somehow a divine existence insofar as they are produced by the gods. ( in tim. i 217. 18 – 27 )


the demiurge. in that respect the physiology seems also to be a sort of theology, since also natural things have somehow a divine existence insofar as they are produced by the gods. ( in tim. i 217. 18 – 27 ) before offering an explanation of the generation of the world, timaeus sets out the fundamental principles that will govern his whole explanation of the physical world ( tim. 27d5 – 28b5 ). as proclus observes, it is the task of a scientist to formulate at the start of his project the principles proper to the science in question, and not just to assume some general axioms. the science of nature too is based on specific axioms and assumptions, which must be clarified before we can move to the demonstration. in order to make phusiologia a real science, the philosopher must deduce his explanation, as does the geometer, from a set of fundamental propositions or axioms. if i may say what i think, it seems to me that plato proceeds here in the manner of the geometers, assuming before the demonstrations the definitions and hypotheses through which he will make his demonstrations, thus laying the foundations of the whole science of nature. ( in tim. i. 217. 18 – 27 ) starting from these fundamental propositions, proclus argues, plato deduces the different types of causality that are required for a truly scientific understanding of nature ( efficient, exemplary, and final cause ; see steel 2003 and above 3. 2 ). time and eternity proclus discusses eternity and time in his commentary on the timaeus and in propositions 53 – 55 of the elements of theology ( see steel 2001 ). aristotle had defined time as a “ measure of movement according to the before and after. ” therefore, anything measured by time must have a form of existence or activity in which a past and a future state can be distinguished. in fact, an entity in time is never wholly and simultaneously what it is, but has an existence extended in a process of before and after. opposed to it stands the eternal, which exists as a simultaneous whole and admits of no composition or change. “ there is no part of it, ” writes proclus, “ which has already subsisted and another that will subsist later, but as yet is not. all that it is capable of being, already possesses it in entirety without losing it or without accumulating ” ( elem. theol. § 52


already subsisted and another that will subsist later, but as yet is not. all that it is capable of being, already possesses it in entirety without losing it or without accumulating ” ( elem. theol. § 52 ). one must distinguish the temporality of things in process from the time by which they are measured. temporal things participate in time, without being time. “ time exists prior to all things in time ” ( elem. theol. § 53 ). with iamblichus, proclus distinguishes absolute time, which is not participated in and exists ‘ prior ’ to all temporal things, from participated time, or rather the many participated times. the same distinctions must also be made regarding eternity. for eternity precedes as cause and measures the multiple eternal beings that participate in it. “ every eternity is a measure of things eternal, every time of things in time ; and these two are the only measures of life and movement in things ” ( elem. theol. § 54 ). to conclude, there are two measures of the duration of things. first there is eternity, which measures at once the whole duration of a being. second, there is time, which measures piecemeal the extension of a being that continually passes from one state to another. eternity can be seen as the prefiguration of time ; time as the image of eternity. each of them governs a separate sphere of reality, eternity the intelligible being, time the temporal ( corporeal and psychic ) world of change. notwithstanding the sharp distinction between the temporal and the eternal realm, there are beings that share in both eternity and time. as proclus notes in the corollary to elem. theol. § 55, “ of the things which exist in time, some have a perpetual duration. ” thus the universe as a whole and the celestial spheres in it are both eternal and temporal. they are eternal because they never come to existence in time and never will cease to exist. but they are temporal because they possess their being only through a process of change in a sequence of moments. the same holds true for the psychic realm : all souls are immortal and indestructible ; nevertheless, they are continually undergoing change. therefore, as proclus says, “ ‘ perpetuity ’ ( aidiotes ) is of two kinds, the one eternal ( aionion ), the other in time ; [ … ] the one having its being concentrated in a simultaneous whole


, as proclus says, “ ‘ perpetuity ’ ( aidiotes ) is of two kinds, the one eternal ( aionion ), the other in time ; [ … ] the one having its being concentrated in a simultaneous whole, the other diffused and unfolded in temporal extension ( paratasis ) ; the one entire in itself, the other composed of parts, each of which exists separately in a sequence of prior and posterior. ” ( elem. theol. § 55, trans. dodds, modified ). the eternity of the world against aristotle ' s critique in de caelo i 10, proclus defends the view that the cosmos is “ both eternal and generated ( genetos ). ” as a corporeal being, the universe cannot produce itself and maintain itself in being. it depends for its existence upon a superior cause, and it is for that reason “ generated. ” this does not prevent it, however, from existing for ever, in an infinite time. as we just saw, proclus distinguishes between what is eternal in an absolute sense ( the intelligible realm ) and what is eternal because it continues to exist for the whole of time, what boethius later called “ aevum ” in distinction from “ aeternum. ” as proclus notices, at the end of the physics ( 8. 10, 266a27 – 28 ), aristotle himself establishes that no body can possess from itself an unlimited power to exist. if the world exists eternally, it must have this power from an incorporeal principle. therefore, aristotle too is forced to admit that the world is somehow generated, though it continues to exist for eternity. for it always receives from its cause its infinite power and never possesses it at once as a whole, because it is limited. the world is eternal, because it has an infinite power of coming to be, not because it exists of infinite power ( in tim. i 252. 11 – 254. 18 ). this disagreement between plato and aristotle is ultimately due to a different view about the first principles of all things. aristotle denies the existence of platonic forms and therefore cannot admit an efficient or creative cause of the universe in the true sense of the word. efficient causality only concerns the sublunary world. the celestial bodies and the world as a whole have no efficient cause of their being, but only a final cause. from this misunderstanding about the first principles follow all the other views that distinguish aristotle from plato. one gets


concerns the sublunary world. the celestial bodies and the world as a whole have no efficient cause of their being, but only a final cause. from this misunderstanding about the first principles follow all the other views that distinguish aristotle from plato. one gets the impression, proclus says, that aristotle, because he could not grasp the first principle of all things - the one – has always to find an explanation of things on a lower level : whatever plato attributes to the one, aristotle attributes to the intellect : that it is without multiplicity, that it is object of desire, that it does not think of secondary things. whatever plato attributes to the demiurgic intellect, aristotle attributes to the heaven and the celestial gods. for, in his view, creation and providence come from them. whatever plato attributes to the substance of heavens [ sc. time ], aristotle attributes to their circular motion. in all these issues he departs from the theological principles and dwells upon the physical explanations beyond what is needed. ( in tim. i 295. 20 – 27 ) the celestial bodies and the place of the universe related to the eternity of the world is the question of the nature of the celestial bodies. aristotle argues in de caelo i 2 that the celestial bodies, which move with a natural circular motion, must be made of a simple substance different from the four sublunary simple bodies ( whose natural movements are in a straight line : up or down ). this ‘ fifth element, ’ which is by nature imperishable, is the ether. with this explanation aristotle seems to oppose the view plato defends in timaeus where it is said that the demiurge made the divine celestial bodies “ mostly out of fire ” ( 40a2 – 4 ). proclus admits that the heaven is composed out of the four elements with a preponderance of fire, but he insists that the elements are not present in the celestial bodies in the same mode as they exist in the sublunary bodies. therefore aristotle is right when he considers the heavens to constitute a fifth nature besides the four elements. “ for in the heavens the elements are not the same as they are here, but are rather the summits of them ” ( in tim. ii 49. 27 – 29 ). if one counts the whole heaven composed out of the best of the elements as one nature and adds to it the four sublunary elements, we may speak of five natures altogether. contrary to aristotle, proclus argues that the whole universe ( to


one counts the whole heaven composed out of the best of the elements as one nature and adds to it the four sublunary elements, we may speak of five natures altogether. contrary to aristotle, proclus argues that the whole universe ( to pan ) is in a place ( topos ). he can do this because his conception of place differs in many respects from aristotle ' s own. the latter defined place as “ the unmoved limit of the surrounding body ” ( physics iv 4, 212a21 – 22 ). from this it follows as a necessary corollary that the universe as a whole cannot be in a place, because there is simply nothing outside it. aristotle ' s definition, as we learn from simplicius ' and philoponus ' corollary on place, had been criticized by all later neoplatonists ( syrianus, proclus, damascius, simplicius, and philoponus ). it is notable that proclus ' own theory of place, as reported by simplicius, differs considerably from other neoplatonic theories in that he considered place an immaterial ‘ body ’, namely a special kind of immobile light. as emerges from proclus ' commentary on plato ' s republic, his theory took inspiration from the column of light mentioned at republic x, 616b. since the heavenly bodies were considered divine, because they are eternal and living beings, the study of the heavens was of special importance to neoplatonists. in the preface to his treatise on astronomical hypotheses ( a summary and evaluation of astronomical views of his time ), proclus makes it clear that his approach is based on plato ' s remarks on astronomy ( especially in the republic and in the laws ). he feels the need to go through the different theories, because one can observe a great disagreement among ancient astronomers on how to explain the different phenomena ( hyp. i § 33 ). fundamental to proclus ' approach is the distinction between two kinds of astronomy ( hyp. i § 1 – 3 ). the first kind contents itself with observing the heavenly phenomena and formulating mathematical hypotheses to explain them and make calculations and prognostics possible. this is the astronomy as practiced by the most famous astronomers before proclus ' time ( aristarchus, hipparchus, and ptolemy ). the second, which is developed by plato in the timaeus, and is confirmed by the tradition of the “


astronomy as practiced by the most famous astronomers before proclus ' time ( aristarchus, hipparchus, and ptolemy ). the second, which is developed by plato in the timaeus, and is confirmed by the tradition of the “ chaldaeans and egyptians, ” investigates into the intelligible causes of heavenly movements. an example for this approach can be found in his commentary on plato ' s republic ( in remp. ii 227. 23 – 235. 3 ). there, proclus explains that the seemingly irregular movements of the planets ought not to be explained by means of ptolemy ' s complicated theory of excentric spheres and epicycles, but are rather due to the fact that the planets are moved by intelligent souls which express in the movements of their bodies “ the invisible powers of the forms ” ( 232. 1 – 4 ). yet proclus appreciates ptolemy ' s astronomy as long as it is seen only as a mathematical - mechanical construction making it possible to calculate and predict the positions of planets, and as long as it does not claim to have any real explanatory value. for the history of astronomy proclus ' astronomical hypotheses remains a most valuable document, since it represents one of the best introductions to ptolemy ' s almagest extant from antiquity and since it explains the most important ancient astronomical theories, in order finally ( in chapter seven of the work ) to evaluate them critically. proclus ' arguments also played an important role in the scientific discussion of the ptolemaic hypotheses in the 16th and 17th century. proclus ' distinctively non - empirical approach towards physics and astronomy also influences his philosophy of mathematics, which is set out in the two prologues to his commentary on the first book of euclid ' s elements. the first prologue deals with the mathematical sciences in general, while the second prologue focuses on geometry proper. proclus argues in great detail that the objects of mathematical sciences cannot be derived from sensible particulars by means of abstraction. because of the imperfect and deficient character of the sensible objects one cannot derive from them objects that are as perfect and as precise as mathematical objects are. therefore, mathematical objects reside primarily in intellect and secondarily in souls ( as logoi ). as universal concepts ( cf. 3. 2 ) we can grasp mathematical objects by means of recollection ( anamnesis ). since geometrical objects are not universal, but particulars, and since by definition they possess extension,


). as universal concepts ( cf. 3. 2 ) we can grasp mathematical objects by means of recollection ( anamnesis ). since geometrical objects are not universal, but particulars, and since by definition they possess extension, proclus argues that their place is human imagination ( phantasia ). imagination acts as a mirror and provides the mathematical objects which are projected into it by the soul with intelligible matter. by means of the latter geometrical objects gain extension and particularity. as with physics and astronomy, the ultimate aim of geometry is not the study of these extended, material objects. rather, geometry serves an anagogical task ( just as in plato ' s republic ), leading the soul upwards to a study of the true and unextended causes of geometrical objects in the divine mind ( in eucl. 54. 14 – 56. 22 ). relying on plato, theaetetus 176a - b late platonists saw the assimilation to god ( homoiosis theoi ) as the goal ( telos ) of philosophy. proclus was faithful to this ideal, as is attested by his biographer marinus ( life of proclus § 25 ). there was a fundamental discussion in late neoplatonism on how this assimilation to the divine was possible for humans. damascius ( in phaed. i § 172 westerink ) distinguishes two tendencies : plotinus and porphyry preferred philosophy, which makes us understand the divine principles of reality through rational explication, while others like iamblichus and his followers, syrianus, and proclus, gave priority to hieratic practice or theurgy ( theourgia, hieratike [ sc. techne ] ). their different evaluation of respectively theory and theurgy as means of salvation may be explained by their different views on the human soul and its possibilities of ascent to the divine realm. while plotinus and porphyry claimed that the superior part of the human soul always remains within the intelligible realm, in touch with the divine principles, and never completely descends into the body, iamblichus, followed by proclus, criticised such a view. the soul does indeed wholly descend into the body ( steel 1976, 34 – 51 ). hence the importance of theurgic rites established by the gods themselves, to make it possible for the human soul to overcome the distance between the mortal and the divine, which cannot be done through increasing philosophical understanding. in


1976, 34 – 51 ). hence the importance of theurgic rites established by the gods themselves, to make it possible for the human soul to overcome the distance between the mortal and the divine, which cannot be done through increasing philosophical understanding. in theol. plat. i 25, proclus expresses his great admiration for the power of theurgy, which surpasses all human knowledge. allegedly, neoplatonic theurgy originated with julian the theurgist, who lived in the time of emperor marcus aurelius. at first sight, theurgy seems to share many characteristics with magic ( theory of cosmic sympathy, invocations, animation of statues of gods and demons ), but it is, as far as we can judge from the extant sources, clearly different from it. in his de mysteriis iamblichus developed a theology of the hieratic rituals from platonic principles, which clearly sets them apart from the vulgar magical practices. while magic assumes that the gods can be rendered subservient to the magicians, platonic philosophers consider this impossible. according to plato ' s principles of theology ( republic ii and laws x ), the gods are immutable, unchangeable, and cannot be bribed by means of sacrifices. proclus ' views on theurgy ( of which only some fragments belonging to his treatise on hieratic art [ i. e., theurgy ] survived ) are fully in line with these fundamental platonic axioms. but how, then, does theurgy work? the theurgists take up an old belief, shared also by many philosophers, namely the natural and cosmic ‘ sympathy ’ ( sumpatheia ) pervading all reality. as with an organism, all parts of reality are somehow linked together as one. another way of expressing this idea is in the neoplatonic principle, going back at least to iamblichus, that everything is in everything ( panta en pasin ). according to proclus, all reality, including its most inferior level, matter, is directed upwards towards the origin from which it proceeds. to say it in the words of theodorus of asine, whom proclus quotes in his commentary on the timaeus ( i 213. 2 – 3 ) : “ all things pray except the first. ” as stated before ( cf. 3. 3 ), the human soul contains the principles ( logoi ) of all reality within itself. the soul


timaeus ( i 213. 2 – 3 ) : “ all things pray except the first. ” as stated before ( cf. 3. 3 ), the human soul contains the principles ( logoi ) of all reality within itself. the soul carries, however, also sumbola or sunthemata which correspond to the divine principles of reality. the same symbols also establish the secret correspondences between sensible things ( stones, plants, and animals ) and celestial and divine realities. thanks to these symbols, things on different levels ( stones, plants, animals, souls ) are linked in a ‘ chain ’ ( seira ) to the divine principle on which they depend, as the chain of the sun and the many solar beings, or the chain of the moon. of great importance in the rituals was also the evocation of the secret divine names. in his commentary on the cratylus, proclus compares divine names to statues of the gods used in theurgy ( in crat. § 46 ), pointing to the fact that also language is an important means in the ascent to the divine. proclus evokes the platonic background of his theurgical beliefs, namely his theory of love ( eros ) as expressed in the symposium and the phaedrus, in his treatise on hieratic art : just as lovers move on from the beauty perceived by the senses until they reach the sole cause of all beautiful and intelligible beings, so too, the theurgists ( hieratikoi ), starting with the sympathy connecting visible things both to one another and to the invisible powers, and having understood that all things are to be found in all things, established the hieratic science. ( trans. ronan, modified ) in the wake of an article of anne sheppard ( 1982 ), scholars usually distinguish between three kinds of theurgy in proclus. the first kind, as described in the above quoted treatise on hieratic art, was mainly concerned with animating statues ( in order to obtain oracles or to evoke divine apparitions ) or, in general, with activities related to physical phenomena or human affairs ( influencing the weather, healing illnesses etc. ) ( see life of proclus § 28 – 29 ). as emerges from our sources, it is this kind of theurgy that involved much ritualistic practice, including hymns and prayers. the second kind of theurgy makes the soul capable of ascending up to the level of the hypercosmic gods and the


sur le parmenide de platon. tome 1, 1re partie : introduction generale, 2e partie : livre i, texte, ( series : collection des universites de france ), paris : les belles lettres ( on this edition see c. steel, mnemosyne 63 ( 2010 ), 120 – 142 ). - morrow, g. r., and j. m. dillon, 1987, proclus ' commentary on plato ' s parmenides, princeton ( new jersey ) : princeton university press. 10. commentary on plato ' s republic ( in different essays ) - kroll, w., 1899 – 1901, procli diadochi in platonis rem publicam commentarii, 2 vol., ( series : bibliotheca scriptorum graecorum et romanorum teubneriana ), leipzig : teubner [ reprint amsterdam : hakkert, 1965 ]. - festugiere, a. - j., 1970, proclus : commentaire sur la republique, 3 vol., ( series : bibliotheque des textes philosophiques ), paris : vrin. 11. elements of physics - ritzenfeld, a., 1912, procli diadochi lycii institutio physica, ( series : bibliotheca scriptorum graecorum et romanorum teubneriana ), leipzig : teubner. - boese, h., 1958, die mittelalterliche ubersetzung der stoicheiosis phusike des proclus, ( series : deutsche akademie der wissenschaften zu berlin, institut fur griechisch - romische altertumskunde, veroffentlichungen 6 ), berlin : akademie verlag. 12. commentary on euclid ' s elements, book i - friedlein, g., 1967, procli diadochi in primum euclidis elementorum librum commentarii, ( series : bibliotheca scriptorum graecorum et romanorum teubneriana ), leipzig : teubner [ reprint hildesheim : olms, 1967 ]. - morrow, g. r., 1970, a commentary on the first book of euclid ' s elements, princeton ( n. j. ) : princeton university press [ reprinted 1992


reprint hildesheim : olms, 1967 ]. - morrow, g. r., 1970, a commentary on the first book of euclid ' s elements, princeton ( n. j. ) : princeton university press [ reprinted 1992, with a new foreword by i. mueller ]. - new edition prepared by c. steel, g. van riel and l. van campe, first volume forthcoming, paris, vrin. 13. exposition of astronomical hypotheses - manitius, c., 1909, procli diadochi hypotyposis astronomicarum positionum, ( series : bibliotheca scriptorum graecorum et romanorum teubneriana ), leipzig : teubner ; reprint stuttgart : teubner 1974. 14. ( frag. ) on the eternity of the world, against the christians ( 18 arguments ) - rabe, h, 1899, ioannes philoponus : de aeternitate mundi contra proclum, leipzig : teubner [ reprint hildesheim : olms, 1963 ]. - lang, h. s., macro, a. d., and j. mcginnis, 2001, proclus : on the eternity of the world ( de aeternitate mundi ), berkeley / los angeles / london : university of california press. - gleede, b., 2009, platon und aristoteles in der kosmologie des proklos. ein kommentar zu den 18 argumenten fur die ewigkeit der welt bei johannes philoponos ( series : studien und texte zu antike und christentum ) tubingen : mohr. 15. ( frag. ) commentary on hesiod, works and days - marzillo, p., 2010, der kommentar des proklos zu hesiods ‘ werken und tagen ’. edition, ubersetzung und erklauterung der fragmente, tubingen : narr. - vogt, e., 1957, procli hymni accedunt hymnorum fragmenta ; epigrammata, scholia, fontium et locorum similium apparatus, indices, wiesbaden : harrassowitz. - van den berg, r. m., 2001, proclus ' hymns : essays, translations, commentary, leiden – boston – koln : brill.


byzantine studies presented to leendert g. westerink at 75., buffalo ( new york ) : arethusa. - reale, g., introduzione a proclo, ( series : i filosofi, 51 ), roma - bari : laterza. - bos, e. p., and p. a. meijer ( eds. ), 1992, on proclus and his influence in medieval philosophy, ( series : philosophia antiqua, 53 ), leiden - koln - new york : brill. - siorvanes, l., 1996, proclus. neo - platonic philosophy and science, new haven : yale university press. - cleary, j. ( ed. ), 1997, the perennial tradition of neoplatonism, ( series : ancient and medieval philosophy, series i, 24 ), leuven : leuven university press. - segonds, a. ph., and c. steel ( eds. ), 2000, proclus et la theologie platonicienne, actes du colloque international de louvain ( 13 – 16 mai 1998 ) en l ' honneur de h. d. saffrey et l. g. westerink, ( series : ancient and medieval philosophy, series i, 26 ), leuven - paris : leuven university press / les belles lettres. - perkams, m., and r. m. piccione ( eds. ), 2006, proklos. methode, seelenlehre, metaphysik, akten der konferenz in jena am 18. - 20. september 2003, ( series : philosophia antiqua, 98 ), leiden - boston : brill. - steel, c., 2006, “ neoplatonism ” and “ proclus, ” in encyclopedia of philosophy, d. m. borchert ( ed. ), detroit : macmillan reference usa, vol. 6, col. 546 – 557 ; vol. 8, col. 40 – 44. - beierwaltes, w., 2007, procliana. spatantikes denken und seine spuren, frankfurt am main : v. klostermann. - steel, c., 2011, “ proclus, ” in the cambridge history of philosophy in late antiquity, l. gerson ( ed. ), cambridge : cambridge university


. sentences, l. brisson ( ed. ), 2 vol., paris : vrin, i, pp. 139 – 274. - – – –, 2007, “ the libraries of the neoplatonists. an introduction, ” in the libraries of the neoplatonists, proceedings of the meeting of the european science foundation ‘ late antiquity and arabic thought : patterns in the constitution of european thought ’ held in strasbourg, march 12 – 14, 2004, c. d ' ancona ( ed. ), ( series : philosophia antiqua, 107 ), leiden - boston : brill, pp. xiii – xxxvi. - d ' ancona, c., and r. c. taylor, 2003, “ liber de causis, ” in dictionnaire des philosophes antiques., r. goulet, j. - m. flamand, and m. aouad, paris : cnrs, pp. 599 – 647. - d ' hoine, p., 2004, “ four problems concerning the theory of ideas : proclus, syrianus and the ancient commentaries on the parmenides, ” in platonic ideas and concept formation in ancient and medieval thought, g. van riel, and c. mace ( eds. ), ( series : ancient and medieval philosophy, series i, 32 ), leuven : leuven university press, pp. 9 – 29. - – – –, 2006, “ the status of the arts. proclus ' theory of artefacts, ” elenchos, 27 : 305 – 344. - de haas, f. a. j., 1997, john philoponus ' new definition of prime matter : aspects of its background in neoplatonism & the ancient commentary tradition, ( series : philosophia antiqua, 69 ), leiden - boston - koln : brill. - di pasquale barbanti, m., 1983, 19932, proclo tra filosofia e teurgia, catania : bonanno. - dillon, j. m., 1972, “ iamblichus and the origin of the doctrine of henads, ” phronesis, 17 : 102 – 106. - – – –, 1986, “ proclus and the forty logoi of zeno, ” illinois classical studies, 11 : 35 – 41. - dillon, j. m., and s.


( pp. 535 – 550 ) ]. - gersh, s., 1973, κινησις ακινητος. a study of spiritual motion in the philosophy of proclus, leiden : brill. - – – –, 1978, from iamblichos to eriugena. an investigation of the prehistory and evolution of the pseudo - dionysian tradition, ( series : studien zur problemgeschichte der antiken und mittelalterlichen philosophie, 8 ), leiden : brill. - gerson, l. p., 1997, “ epistrophe eis heauton : history and meaning, ” documenti e studi sulla tradizione filosofica medievale, 8 : 1 – 32. - – – –, 2005, aristotle and other platonists, ithaca – london : cornell university press. - gritti, e., 2008, proclo. dialettica, anima, esegesi, ( series : il filarete, collana die studi e testi ), milano : led. - gunther, h. - chr., 2007, die uebersetzung der elementatio theologica des proklos und ihre bedeutung fur den proklostext, leiden : brill. - hankins, j., and w. bowen ( eds. ), 2001 – 2006, marsilio ficino. platonic theology, 6 vol., ( series : i tatti renaissance library ), cambridge ( mass. ) : harvard university press. - hankinson, r. j., 1998, cause and explanation in ancient greek thought, oxford : clarendon. - halfwassen, j., 1999, hegel und der spatantike neuplatonismus. untersuchungen zur metaphysik des einen und des nous in hegels spekulativer und geschichtlicher deutung, ( series : hegel studien, 40 ), bonn : bouvier. - harari, o., 2006, “ methexis and geometrical reasoning in proclus ' commentary on euclid ' s elements, ” oxford studies in ancient philosophy, 30 : 361 – 389. - helmig, c., 2004, “ what is the systematic place of abstraction and concept formation in plato


proclus ' commentary on euclid ' s elements, ” oxford studies in ancient philosophy, 30 : 361 – 389. - helmig, c., 2004, “ what is the systematic place of abstraction and concept formation in plato ' s philosophy? ancient and modern readings of phaedrus 249b - c, ” in platonic ideas and concept formation in ancient and medieval thought, g. van riel, and c. mace ( eds. ), ( series : ancient and medieval philosophy, series i, 32 ), leuven : leuven university press, pp. 83 – 97. - – – –, 2008, “ proclus and other neoplatonists on universals and predication, ” documenti e studi sulla tradizione filosofica medievale, 19 : 31 – 52. - – – –, 2009, “ ‘ the truth can never be refuted ’ – syrianus ' view ( s ) on aristotle reconsidered, ” in syrianus et la metaphysique de l ' antiquite tardive, a. longo ( ed. ), ( series : elenchos, 51 ), rome : bibliopolis, 347 – 380. - – – –, 2010, “ proclus ' criticism of aristotle ' s theory of abstraction and concept formation in analytica posteriora ii 19 and elsewhere, ” in interpreting aristotle ' s posterior analytics in late antiquity and beyond, f. a. j. de haas, and m. e. m. p. j. leunissen, and m. martijn ( eds. ), ( series : philosophia antiqua, 124 ), leiden – boston – koln : brill, 27 – 54. - – – –, 2011, forms and concepts — concept formation in the platonic tradition. a study on proclus and his predecessors, ( series : philosophia antiqua ), leiden – boston – koln : brill [ forthcoming ]. - klibansky, r., 1981, the continuity of the platonic tradition during the middle ages, with a new preface and four supplementary chapters together with plato ' s parmenides in the middle ages and the renaissance, with a new introductory preface, munchen : kraus. - kremer, k., 1966, 19712, die neuplatonische seinsphilosophie und ihre wirkung auf thomas von aquin


renaissance, with a new introductory preface, munchen : kraus. - kremer, k., 1966, 19712, die neuplatonische seinsphilosophie und ihre wirkung auf thomas von aquin, ( series : studien zur problemgeschichte der antiken und mittelalterlichen philosophie, 1 ), leiden : brill. - kuisma, o., 1996, proclus ' defense of homer, ( series : commentationes humanarum litterarum, 109 ), helsinki : societas scientiarum fennica. - kutash, e., 2011, ten gifts of the demiurge : proclus on plato ' s timaeus, london / new york : bristol classical press. - lang, h. s., 2005, “ perpetuity, eternity, and time in proclus ' cosmos, ” phronesis, 50 : 150 – 169. - lernould, a., 1987, “ la dialectique comme sciene premiere chez proclus, ” revue des sciences philosophiques et theologiques, 71 : 509 – 535. - – – –, 2001, physique et theologie : lecture du timee de platon par proclus, villeneuve d ' ascq ( nord ) : presses universitaires du septentrion. - linguiti, a., 1990, l ' ultimo platonismo greco : principi e conoscenza, ( series : accademia toscana di scienze e lettere la colombaria. studi, 112 ), firenze : olschki. - lloyd, a. c., 1990, the anatomy of neoplatonism, oxford : clarendon. - mansfeld, j., 1994, prolegomena : questions to be settled before the study of an author, or a text, ( series : philosophia antiqua, 61 ), leiden : brill. - martijn, m., 2010, proclus on nature. philosophy of nature and its methods in proclus ' commentary on plato ' s timaeus, ( series : philosophia antiqua, 121 ), leiden : brill. - o ' meara, d. j., 1986, “ le probleme de la metaphysique


commentary on plato ' s timaeus, ( series : philosophia antiqua, 121 ), leiden : brill. - o ' meara, d. j., 1986, “ le probleme de la metaphysique dans l ' antiquite tardive, ” freiburger zeitschrift philosophie und theologie, 33 : 3 – 22. - – – –, 1989, pythagoras revived. mathematics and philosophy in late antiquity, oxford : clarendon. - opsomer, j., 2000, “ proclus on demiurgy and procession. a neoplatonic reading of the timaeus, ” in reason and necessity. essays on plato ' s ‘ timaeus ’, m. r. wright ( ed. ), london : duckworth, pp. 113 – 143. - – – –, 2001, “ proclus vs plotinus on matter ( de mal. subs. 30 – 7 ), ” phronesis, 46 : 154 – 188. - – – –, 2003, “ la demiurgie des jeunes dieux selon proclus, ” les etudes classiques, 71 : 5 – 49. - – – –, 2006, “ to find the maker and father. proclus ' exegesis of plato tim. 28c3 – 5, ” etudes platoniciennes, 2 : 261 – 283. - opsomer, j., and c. steel, 1999, “ evil without a cause : proclus ' doctrine on the origin of evil, and its antecedents in hellenistic philosophy, ” in zur rezeption der hellenistischen philosophie in der spatantike, akten der 1. tagung der karl - und - gertrud - abel - stiftung vom 22. - 25. september 1997 in trier, th. fuhrer, and m. erler ( eds. ), ( series : philosophie der antike, 9 ), stuttgart : steiner, pp. 229 – 260. - phillips, j., 2007, order from disorder. proclus ' doctrine of evil and its roots in ancient platonism, ( series : ancient mediterranean and medieval texts and contexts ; studies in platonism, neoplatonism, and the platonic tradition, 5 ), leiden : brill. - pichler, r., 2006, allegorese und ethik bei pro