In search of an alternative explanation, we next investi- gated a possible T-cell excitatory effect of calcium (Quintana et al., 2011; Monaco et al., 2016) in our model.

Purified human and murine T cells were exposed to various calcium concentrations ranging from 1 to 3 mM (Fig. 7A-H).

Importantly, in these in vitro assays we extended the range to include lower concentrations of cal- cium, having in mind that in the serum of our vitamin D- treated mice a substantial proportion is bound to protein (Fig. 1B, C and Supplementary Fig. 6A), which may reduce its direct availability for T cells proportionally.

As shown in Fig. 7A and B, calcium dose-dependently accelerated pro- liferation of both human and murine CD4 + and CD8 + T- cells in this setting, while chloride levels, pH and T-cell viability remained unaffected (Supplementary Fig. 6B-E).

Further dissecting this observation, we monitored the cellu- lar calcium influx upon T-cell activation (Gwack et al., 2007).

To account for a protein-reduced medium in these assays we used a lower range of total calcium concentra- tions (Supplementary Fig. 6F) and checked again that chlor- ide levels and pH remained unaffected (Supplementary Fig. 6G and H).

As indicated in Fig. 7C and D, raising extra- cellular calcium to concentrations again equivalent to the serum levels of ionized calcium in our vitamin D fed mice caused a significant increase in the mean calcium influx, triggering an upregulation of pro-inflammatory gene prod- ucts (Fig. 7E and F).

Lastly, we corroborated that this direct T-cell stimulating effect of calcium also occurred in vivo.

For this purpose, we repetitively and continuously


Geographical latitude correlates with multiple sclerosis in- cidence (Acheson et al., 1960) which highlights the influ- ence of environmental factors in multiple sclerosis (Ascherio and Munger, 2007).

Lack of exposure to sun- light, UV radiation and hereby relatively low levels of vita- min D in the context of its emerging immunoregulatory properties provides one attractive explanation for this cor- relation (Nielsen et al., 2017); the central question remain- ing though is whether lack of vitamin D is causal in triggering multiple sclerosis activity or an epiphenomenon of insufficient sun light exposure as the true risk factor (Schwarz et al., 2012).

A direct effect of vitamin D on multiple sclerosis activity is yet the conceptual requirement for all current efforts to therapeutically raise its level in affected patients.

Empiric vitamin D supplementation stu- dies thus far have provided conflicting results (Stein et al., 2011; Loken-Amsrud et al., 2012).

For example, adding vitamin D3 to interferon treatment reduced MRI activity in a small trial with relapsing-remitting multiple sclerosis patients (Soilu-Hanninen et al., 2012), which was recently confirmed by a larger phase II study (Hupperts et al., 2017).


Unfortunately, the conclusions from these studies are limited as both interferon-beta (IFNb) and vitamin D interact in modulating multiple sclerosis disease activity, and data indicate that sufficient vitamin D is a prerequisite for the benefit of IFNb (Stewart et al., 2012).

While available data indicate that moderate vitamin D supplemen- tation is safe in multiple sclerosis (Sotirchos et al., 2016), results of ongoing larger placebo-controlled trials are needed to clarify whether therapeutic vitamin D supplemen- tation is beneficial in multiple sclerosis independent of con- comitant disease modifying therapy.


Our results suggest that modest vitamin D supplementa- tion may have a beneficial effect in EAE, while those data were not significant.

We report here, to our knowledge for the first time, that continuous supplementation with high doses of vitamin D yet exerted a highly significant para- doxical effect, promoting exacerbation of clinical and histo- logical EAE.

This outcome was underpinned by an accentuated phenotype and function of myeloid APC as well as an unleashed development of pro-inflammatory T cells upon high dose vitamin D treatment.

Further, high- dose vitamin D similarly accelerated activation and differ- entiation of both myeloid APC and T cells in unimmunized healthy mice (Fig. 5F, G and Supplementary Fig. 7), indi- cating that the high vitamin D dose exerted a broad immune cell activating effect independent of an inflamma- tory context.


At first glance, these findings appear to con- flict with several other experimental studies, which mainly reported a clinical benefit of vitamin D treatment in EAE, also at higher doses (Lemire and Archer, 1991; Cantorna et al., 1996; Nashold et al., 2000); however, all of these studies evaluated short-term vitamin D supplementation.

In most of these studies, hydroxylated forms of vitamin D were investigated in a brief intervention regimen.

Most likely as a result, none of these studies reported develop- ment of hypercalcaemia.

Elevated serum calcium was, how- ever, observed in another study continuously exposing mice to high doses of vitamin D (Spach and Hayes, 2005), again suggesting that it may develop only after an extended period of exposure.


The strength of our study is that we supplemented vitamin D for several months before assess- ing EAE susceptibility, and that we fed cholecalciferol, the metabolite supplemented in humans.

As a result, we mea- sured serum levels of 25-(OH) vitamin D, again the mol- ecule most commonly assessed in humans, reflective of patients with multiple sclerosis considered vitamin D-defi- cient, with physiological or high vitamin D levels


Binding of vitamin D to immune cells and subsequent VDR signalling regulates pro-inflammatory immune func- tions (Peelen et al., 2011) and is likely of benefit in sup- pression of CNS autoimmune disease (Meehan and DeLuca, 2002; Xie et al., 2017).

In line with these studies, our in vitro results confirm a direct beneficial effect of vita- min D and its metabolites on T cells (Peelen et al., 2011), inhibiting their activation and pro-inflammatory differenti- ation.

Of note, the extent of this effect was consistently greater on CD8 + than on CD4 + T cells, following the relative expression levels of the VDR on these cells (Veldman et al., 2000).

Interestingly, B cells can only react to vitamin D after initial activation and subsequent upregulation of the VDR, as their constitutive expression is relatively low (Provvedini et al., 1983, 1986).

Nevertheless, 1,25(OH) 2 D 3 has been shown to reduce B-cell prolifer- ation, plasma and memory cell differentiation and induced apoptosis in proliferating B cells (Chen et al., 2007).


These findings suggest that the direct effect of vitamin D on both human and murine lymphocytes is indeed of anti- inflammatory nature and most likely beneficial in an auto- immune setting.


Our results indicate that in contrast, a rise in the serum calcium exerts the opposite effect on T cells, which can ap- parently override any clinical benefit of vitamin D in EAE.

This is in line with the earlier finding that adding the cal- cium-lowering hormone calcitonin additively augmented the therapeutic benefit of a vitamin D in EAE (Becklund et al., 2009).

Calcium acts as a second messenger promoting cell cycle progression in many cell types, including lymphocytes (Feske, 2007).

T-cell receptor signalling raises intracellular calcium at first by its release from the endoplasmatic reticu- lum, and to the greater extent by subsequent extracellular calcium influx through plasma membrane calcium channels (Kuno and Gardner, 1987; Lewis, 2001).

Only the latter is capable of raising intracellular and nuclear calcium levels over an extended period of time, which is required to pro- mote activation, proliferation and differentiation of immune cells (Dolmetsch et al., 1998; Vig and Kinet, 2009), includ- ing clonal expansion of T cells (Vaeth et al., 2017).


This is precisely the scenario and the sequence of events which we identified to underlie deterioration of EAE severity in our study.

Modelling hypercalcaemia at the levels observed upon continuous high dose vitamin D treatment in vivo acti- vated T cells independent of vitamin D. Mechanistically, an elevated level of calcium triggered its increased influx into T cells upon activation, which led to an upregulation of pro- inflammatory gene products.

These initial events were fol- lowed by an unleashed proliferation and encephalitogenic differentiation of both human and murine T cells, corrobor- ating a causal sequence of high dose vitamin D treatment, secondary hypercalcaemia and a promoted development of disease-driving encephalitogenic T cells.

While there is cur- rently no molecule to selectively interfere with the calcium influx into immune cells in vivo, genetically determined in- ability of these calcium channels to function in T cells com- pletely blocked EAE by preventing development of myelin- reactive Th1 and Th17 cells (Ma et al., 2010).

Along the same lines, therapeutic blockade of calcium channels by nimodipine was recently reported to suppress EAE (Schampel et al., 2017).

This clinical benefit was primarily attributed to restored remyelination, but furthermore, may relate to attenuated T-cell activation.

In conjunction, these findings indicate that worsening of EAE in our high vitamin D group indeed occurred as a consequence of raising the mean calcium level.

In greater context, these data implicate that the clinically desirable effect of modest vitamin supple- mentation may be reflective of immune-regulatory VDR sig- nalling, while exacerbation of T cell-mediated CNS autoimmunity at excessive vitamin D doses is primarily attributed to raising the mean calcium level.


Hypercalcaemia in its extent comparable to the levels associated with deterioration of EAE commonly occurs in humans supplemented with high doses of vitamin D (Malihi et al., 2016).

In conjunction with these observations, our novel findings highlight excessive vitamin D supplementation and resulting hypercalcaemia as novel risk factors promot- ing worsening of CNS demyelinating disease.

Our data cau- tion that in light of the currently limited information on a direct beneficial effect of vitamin D in multiple sclerosis, patients with multiple sclerosis may be at danger of experi- encing untoward immunological and/or clinical effects when vitamin D is supplemented excessively.


We read the recent paper of Ha¨usler et al. ( 2019) with great interest.

The authors report observations in the experimental autoimmune encephalomyelitis (EAE) model suggesting that vitamin D3-induced hypercalcaemia is detrimental for the disease course of multiple sclerosis.

The main sign of vitamin D toxicity is hypercalcaemia, which can lead to loss of kidney function and cardiovascular complications, among others [1].

Ha¨usler et al. show that high calcium levels exacerbate immunological processes potentially harmful for neuroinflammation of multiple sclerosis.

In their experiments, 10 weeks of high-dose vitamin D3 in C57BL/6 mice (n = 8) induced 25(OH)D levels exceeding 200 nmol/l, a rise of circulating calcium levels, and a steep increase in urine calcium levels [2].

We performed several supplementation studies using high-dose vitamin D3 supplements in patients with multiple sclerosis, and did not observe these dramatic effects on markers of calcium metabolism.


A safety study of 12 weeks of 500 mg/d (20 000 IU/d) vitamin D3 supplements in 15 interferon beta-treated participants with relapsing remitting multiple sclerosis (RRMS) showed no cases of hypercalciuria, defined as a spot urine calcium/creatinine ratio exceeding 1.0 mM/mM [3].

Additionally, no cases were observed of hypercalcaemia, defined as serum calcium levels exceeding 2.6 mmol/l.

At group level, serum calcium levels remained stable.

Serum 25(OH)D levels were elevated to a median level of 380 nmol/l.

One relapse of multiple sclerosis occurred at Week 7, another at Week 19 during the safety follow-up.

No increases in CD4 + T cells producing interferon gamma (IFN-γ) or interleukin 17 (IL-17) were noted.


In the SOLAR trial, 48 weeks of 350 mg/d (14 000 IU/d) vitamin D3 supplements in n = 113 versus placebo in n = 116 interferon beta-treated participants with RRMS did not show any cases of hypercalcaemia using the same definitions [4].

There were two cases of mild-to-moderate hypercalciuria in the vitamin D3, and three in the placebo group.

Serum 25(OH)D levels were elevated to a median level of 215 nmol/l.

There was no difference in proportion of participants free of disease activity between the treatment arms; secondary MRI endpoints suggested benefit in the vitamin D3 arm.

In a subgroup of Dutch participants, no increases in CD4 + T cells producing IFN-γ, IL-17 or granulocyte macrophage colony stimulating factor (GM-CSF) were noted [5].


In a 16-week study of 100 mg/d (4 000 IU/d) vitamin D3 supplements in 25 first line disease-modifying drug-treated participants with RRMS versus placebo (n = 23), no cases of hypercalcaemia were observed, using the same definitions [6].

At the Week 8 visit, there were five cases of hypercalciuria, three in the placebo and two in the vitamin D3 arm, which all resolved spontaneously.

Serum 25(OH)D levels were elevated to a median level of 139.9 nmol/l.

Two relapses were recorded, one in the vitamin D3 and one in the placebo arm.

No increases in CD4 + T cells producing IFN-γ, IL-17, or GM-CSF were noted [7].


The effects of increased 25(OH)D levels on serum and urine calcium levels in inbred mouse strains suffering from EAE cannot be extrapolated to people suffering from multiple sclerosis.

However, the data of Ha¨usler et al. stress the importance of monitoring calcium metabolism carefully in clinical studies on high doses of vitamin D3 in multiple sclerosis [8].

High-dose vitamin D3 supplements without hypercalcaemia were not associated with adverse multiple sclerosis outcomes, or with a more pro-inflammatory composition of the T cells.

These observations are supported by several other controlled studies on moderate to high-dose vitamin D3 supplementation in multiple sclerosis [9][10][11][12][13][14].

The question whether supplementing such high doses of vitamin D3 is of any additional benefit on relevant multiple sclerosis endpoints when compared to moderate doses should become clear from controlled studies comparing these doses or meta-analyses of clinical trials.


Hereby we would like to reply to the comments by Smolders et al. ( 2019) regarding our recent publication describing a clinical deterioration in a murine model of multiple sclerosis upon high-dose vitamin D supplementation, which is mediated by a T cell-stimulatory effect of secondary hypercalcaemia [1].

Smolders et al. highlight that several high-dose vitamin D supplementation studies in multiple sclerosis patients reaching 25(OH)D median levels of up to 380 nmol/l reported no hypercalcaemia [2][3] and only single cases of hypercalciuria [4] occurring in both the treatment and placebo groups.

Moreover, the authors described no development of pro-inflammatory T cells after high-dose vitamin D supplementation, concluding that hypercalcaemia rather than high-dose vitamin D3 supplements could exacerbate multiple sclerosis.


We agree with this suggestion, observing that a moderate dose of vitamin D suppressed experimental autoimmune encephalomyelitis (EAE) and that direct in vitro exposure of murine or human T cells to vitamin D and its metabolites even at supra-physiological doses inhibited proliferation and pro-inflammatory differentiation.

By contrast, directly exposing murine, but also human CD4+ and CD8+ T cells to hypercalcaemic concentrations caused an increased susceptibility to activation, an upregulation of pro-inflammatory gene products as well as an enhanced capacity of activated T cells to transmigrate across a blood–brain barrier model.

Moreover, raising calcium concentrations directly in vivo resulted in increased expression of activation markers on CD4+ and CD8+ T cells.


We want to emphasize that our investigations hereby support that vitamin D itself exerts a favourable effect in inflammatory CNS demyelinating disease; furthermore, we fully agree that our experimental data by no means can be used to extrapolate how regularly and/or persistently hypercalcaemia occurs upon high-dose vitamin D supplementation in patients with multiple sclerosis; to date it indeed has only been reported in a few cases on high dose vitamin D therapy, especially when combined with calcium intake [5][6][7].

Yet we believe that our mechanistic observations caution that an uncritical and continuous supplementation with very high doses of vitamin D as propagated by few individuals in the field may not be advisable, especially when possible effects on the calcium metabolism are not regularly monitored.

In this situation, the undesirable effects of hypercalcaemia, including the newly reported activation of potentially pathogenic T cells, may indeed occur more frequently and outweigh any possible benefit of vitamin D itself.


We believe that the comments by Smolders et al. thus adequately contextualize our experimental data, and that we can jointly conclude on the note that moderation and monitoring may be advisable in vitamin D supplementation of multiple sclerosis.


Participants in the Multiethnic Cohort Study were re- cruited between 1993 and 1996 through targeted mailings to men and women aged 45-74 years.

A total of 215,251 men and women completed a self-administered baseline questionnaire that obtained information on medical history, family cancer history, diet, medication usage, physical ac- tivity, smoking history, alcohol intake, and women's repro- ductive history, including menopausal status and hormone use.

A description of the methods used to create the cohort and the characteristics of cohort members has been pub- lished elsewhere (19).

The proposal for this work was ap- proved by the institutional review boards of the University of Southern California and the University of Hawai'i.

Informed consent was obtained in writing from cohort par- ticipants, as per the protocol.


A total of 103,893 female African-American, Japanese- American, Native Hawai'ian, Latina, and non-Latina White cohort members with no history of breast, ovarian, or endo- metrial cancer were eligible for this study.

Of these, 95,704 women with a mean age of 59.7 years (10th-90th percentile range, 47.0-71.0) had valid nonmissing data for the vari- ables of interest and were included in the final analysis (table 1).

Only data from the baseline questionnaire were used in the current analysis.


A woman was considered postmenopausal if her men- strual periods had stopped naturally or if she had undergone a hysterectomy or bilateral oophorectomy.

Women in the second category were censored in this analysis, as were pre- menopausal women.

For 1,452 women who were missing data on age at menopause but for whom we had data on when they began using hormone therapy, the age at initiation of hormone therapy was assigned as the age of menopause.


Age at menopause was recorded in the baseline question- naire in four categories: <45, 45-49, 50-54, and 55 years.

Women who were older at baseline than the maximum age of the selected category were assigned an event age at the midpoint of the category (43, 47, 52, or 57 years).

If a subject's age at baseline was within the category she se- lected for her age at natural menopause, her event age was calculated as the midpoint between the start of the category and her age at baseline.

Premenopausal subjects were as- signed a censoring age in a parallel manner.

For example, a 53-year-old premenopausal woman was censored at age 51.5 years, the midpoint between her age at menopause and the start of the corresponding age-at-menopause category.


Categories of age at hysterectomy or bilateral oophorec- tomy were <45, 45-49, and 50 years.

Subjects reporting menopause by surgery in one of the first two categories (<45 years or 45-49 years) were assigned a censoring age in a manner parallel to the manner in which naturally men- opausal subjects were assigned an event age.

Women with surgical menopause whose age at baseline was older than the highest age of the self-reported age-at-surgery category were assigned a censoring age at the midpoint of the self- reported age-at-surgery category (43 years or 47 years).

If a subject's age at baseline fell within the category she se- lected for her age at surgery, the censoring age was calcu- lated as the midpoint between the start of the category and her baseline age.

Subjects reporting menopause by surgery in the highest category (50 years) were treated in a differ- ent manner, because the age at natural menopause had one additional category on the upper end (55 years).

Subjects between 50 and 54 years of age at baseline were assigned a censoring age at the midpoint between their baseline age and 50 years.

Subjects aged 55-57 years at baseline were censored at the midpoint between their baseline age and 55 years, and those older than 57 years at baseline were censored at age 57 years.


In addition to race/ethnicity, we considered the following factors, on which data were collected at baseline, as poten- tial predictors of the timing of natural menopause: smoking history, age at menarche, age at first full-term pregnancy, parity, years of oral contraceptive use, and body mass index (weight (kg)/height (m) 2 ).

Table 1 shows the categories used for each of these factors.

Smoking history was defined by a six-level variable that separated women whose smoking might have been temporally relevant to menopause (never smoker, smoker who started smoking after age 45 years, smoker who quit before age 45 years and smoked 10 cig- arettes per day, smoker who quit before age 45 years and smoked >10 cigarettes per day, current smoker at age 45 years who smoked 10 cigarettes per day, and current smoker at age 45 years who smoked >10 cigarettes per day).

Body mass index was categorized according to World Health Organi- zation guidelines (<20, 20-24.9, 25-29.9, or 30) (20).


We used univariable and multivariable Cox proportional hazards regression with age as the time metric (21) to assess the association (hazard ratio) between exposure and out- come variables.

Subjects were considered to have entered the study at birth and remained under follow-up until they completed the baseline questionnaire (when they joined the Multiethnic Cohort Study) or until one of the following events occurred: natural menopause (event) or surgery re- sulting in the end of menses, including hysterectomy and/or bilateral oophorectomy (censored observation).

Thus, women who were premenopausal at baseline were censored at the A series of univariable analyses were performed in which a model with each single variable of interest was tested by likelihood ratio test against a model that fitted only an in- tercept term.

Variables showing statistically significant as- sociations with timing of natural menopause in univariable analyses were subsequently tested for independent associa- tions in a multivariable model.

We fitted a series of multi- variable failure-time models in which a woman failed at the time of natural menopause and which included both race/ ethnicity and smoking to determine the factors associated with the relative timing of natural menopause.

A forward stepwise regression approach was used, with variables enter- ing the model when at least one of the categories had a p value less than 0.01.

Once a full model was identified, a backward stepwise regression approach was used, with variables being excluded when no category had a p value less than 0.01.

Trend tests for ordinal variables were performed by fitting as a single variable the ordinal categories of increasing expo- sure.

A test for interaction with race/ethnicity was performed on each covariate retained in the final model.

All statistical significance levels (p values) quoted are two-sided.

An alpha level of 0.05 was used as the threshold for statistical signif- icance, unless otherwise explicitly stated.


The study population included a substantial proportion of Japanese-American (27.8 percent), non-Latina White (25.4 percent), Latina (20.8 percent), and African-American (18.8 percent) women (table 1).

In addition, 7.2 percent were Native Hawai'ians.

Of the Latinas, 48.5 percent had been born outside of the United States.

A chi-squared test for the difference in the proportions of subjects by racial/ethnic group for each variable shown in table 1 was statistically significant (all p's 0.01).


In characterizing the study pop- ulation, African Americans tended to be somewhat heavier and to have earlier first full-term pregnancies and were more likely to have undergone surgical menopause (hysterectomy and/or bilateral oophorectomy (43.1 percent)) than women in any of the other racial/ethnic groups.

In table 1, partic- ipants in the category of surgical menopause by bilateral oophorectomy may also have had a hysterectomy, whereas participants categorized as having undergone surgical men- opause by hysterectomy had only ever had a hysterectomy.


Native Hawai'ians were the youngest of the racial/ethnic groups and were relatively overweight.

Japanese Americans were leaner, were less likely to smoke (as were the non-US- born Latinas), and had a later age at first full-term pregnancy than women in other racial/ethnic groups.

A greater propor- tion of non-Latina Whites were nulliparous than women in other racial/ethnic groups.

Non-US-born Latinas had later ages at menarche than US-born Latinas.


In the univariable analyses, race/ethnicity and smoking were significantly associated with the timing of natural menopause (data not shown).

Thus, in testing of additional variables, we retained race/ethnicity and smoking in the models.

Age at menarche, age at first full-term pregnancy, parity, years of oral contraceptive use, and body mass index were significantly associated with relative timing of natural menopause in univariable analyses with race/ethnicity and smoking forced into the model.

Of these factors, age at menarche, parity, and body mass index were significantly independently associated with relative timing of natural menopause in the multivariable model, in addition to race/ ethnicity and smoking (table 2).


In table 2, the independent effect of race/ethnicity in the timing of natural menopause in the multivariable model is evident.

Latinas, particularly those not born in the United States, experienced significantly earlier menopause than did non-Latina Whites (non-US-born Latinas: hazard ratio (HR) ¼ 1.25, 95 percent confidence interval (CI): 1.21, 1.30; US-born Latinas: HR ¼ 1.10, 95 percent CI: 1.07, 1.14).

Native Hawai'ians showed a borderline-significant effect that pointed in the same direction as the effect for Latinas (HR ¼ 1.05, 95 percent CI: 1.01, 1.09).

African Americans did not differ significantly from non-Latina Whites (HR ¼ 0.99, 95 percent CI: 0.96, 1.02).

Japanese Americans expe- rienced later menopause than non-Latina Whites (HR ¼ 0.93, 95 percent CI: 0.90, 0.95).

Race/ethnicity-specific hazard ra- tios were obtained from a series of models in which race and smoking were forced in and into which each covariate associ- ated with the timing of natural menopause was added in- dividually.

A comparison of these models showed no alteration in the race/ethnicity-specific hazard ratios (data not shown).


Age at natural menopause in the developed world is ap- proximately normally distributed, ranging between 40 years and 58 years, with an approximate mean of 51.4 years (22).

This broad range may be due to real differences in age at natural menopause, driven by variation in an incom- pletely defined set of predictors.

It may also be attributed to methodological issues, including differing or problematic methods of classification of menopausal status, use of con- venience samples such as hospital patients, potentially in- accurate recall in retrospective assessment of age at event and covariate information, inconsistent treatment of hormone therapy users, lack of data on demographic and physiologic covariates, and paucity of data on diverse pop- ulations (see reviews by the World Health Organization (23) and Crawford (24)).


In the current study, we investigated a host of lifestyle and reproductive variables that may influ- ence the timing of natural menopause in the large, population- based Multiethnic Cohort Study cohort.

In this racially/ ethnically diverse study of over 90,000 women, Japanese- American race/ethnicity was independently associated with relatively late natural menopause and Latinas were found to experience relatively early natural menopause, with those born in the United States experiencing the event later than those born outside the United States.

Adjustment for other factors did not significantly alter the magnitude of these racial/ethnic effects.


Most previous studies that assessed predictors of the tim- ing of natural menopause did not address whether the timing of natural menopause differed by race/ethnicity, because of the predominance of European ancestry in the study popu- lations (6, 25-31).

The findings of one prospective study (13) and three cross-sectional studies (14-16) suggested that African-American women experienced natural menopause earlier than non-Latina Whites; Gold et al. ( 17) reported that Japanese Americans experienced menopause later than non- Latina Whites.

None of these findings were conclusive.


The independent racial/ethnic effect reported in this study does not discount the hypothesis that age at natural meno- pause is a heritable trait.

Torgerson et al. ( 8) reported an association between age at natural menopause and maternal age at natural menopause in a study of 551 women.

Inves- tigators have reported heritability estimates for age at natural menopause that have ranged from 31 percent to 63 percent (11, 12, 32, 33).

Genome-wide linkage studies with age at natural menopause as a continuous quantitative phenotype have identified several loci with strong signals (34, 35).

Other studies have suggested associations with single nucleotide polymorphisms in genes in several pathways (36-41).


Of all environmental factors studied previously, smoking has been most consistently associated with the timing of natural menopause (17, 42-48).

We have reported a dose- response relation between timing and amount of smoking and age at natural menopause that is consistent with evi- dence from a quantitative review (49).

The mechanism by which smoking affects the timing of natural menopause is not fully understood, and it is likely to involve more than one pathway (50-53).


Reproductive factors, particularly those hypothesized to influence ovulation or follicle attrition, are somewhat contro- versial with respect to timing of natural menopause.

The di- rection of our results regarding age at menarche (54) and parity (13, 25, 27, 48) is consistent with previous reports.

In our data, it appears that women with a low body mass index (body mass index <20) have an earlier age at natural meno- pause than heavier women.

In the postmenopausal period, women with a high body mass index have higher circulating levels of estrogen than leaner women through the increased aromatization of androstenedione that occurs in body fat (55).

It is possible, in women transitioning through menopause (i.e., perimenopausal women), that some additional adipose- tissue-derived estrogen may support the continuation of menstrual cycles in heavier women relative to leaner women.


The current study had several strengths.

The multiethnic design enabled us to attempt to address whether the timing of natural menopause differed by racial/ethnic group.

Ex- tensive information from the baseline questionnaire offered us the opportunity to assess racial/ethnic variation in the timing of natural menopause while controlling for a number of potentially confounding factors.

Use of a failure-time modeling approach enabled us to avoid excluding a large proportion of subjects.


However, this analysis was potentially limited by several factors.

In particular, this is a cross-sectional data set and it may contain errors in recall.

For example, we might predict that increased error in recall would be associated with in- creasing age or decreasing socioeconomic status.

To assess this quantitatively, we conducted an analysis limited to women who were less than 60 years of age at baseline.

We also tested the addition of an attained education variable (high school or less, some college/vocational school, college graduation or higher) as a surrogate for socioeconomic sta- tus.

Finally, we limited the analysis to women with an edu- cation in the higher two categories.

With no method did any of the race/ethnicity-specific hazard ratios change by more than 10 percent.

These results argue against differential re- call by age and socioeconomic status.


Another limitation stems from the fact that the variable for age at natural menopause was categorical, which pre- vents the easy translation of the hazard ratios into a differ- ence in years or months.

However, to provide an idea of what a hazard ratio means in terms of months, we used a method published by Krailo et al. ( 56).

Assuming a median age at natural menopause of 50 years, a hazard ratio of 1.25, corresponding to the largest multivariate race/ethnicity- specific hazard ratio reported herein, which was specific to the non-US-born Latinas, would translate into a difference of 0.72 years or 8.64 months.


In addition, there was a small group of women (n ¼ 1,452; 1.5 percent of the total) who were missing data on age at menopause but for whom we had data on when they began using hormone therapy.

For these women, we defined age at menopause as the age at which they reported starting the use of hormone therapy.

By definition, these women will tend to have been assigned a menopausal age lower than their true age at menopause.

This would mean that groups with higher proportions of such women would appear to have had an earlier meno- pause.

We tested whether our coding was biasing our results in several ways, including 1) entering an indicator variable (1 ¼ age at menopause assigned as age at first use of hor- mone therapy, 0 ¼ age at menopause known) in the final multivariable model, 2) censoring the women with an age at menopause assigned as age at first use of hormone therapy at the age at first use of hormone therapy, and 3) excluding all of the women with an age at menopause assigned as age at first use of hormone therapy.

There was no significant change in the race/ethnicity-specific hazard ratios, indicat- ing that our coding did not produce material bias.


The categorical nature of these data also posed a problem in choosing a method for assignment of censoring ages.

We tested methods extensively.

For example, for women older than 55 years at baseline who reported an age at surgical menopause of 50 years or older, we tested several methods, including one in which we assigned a censoring age based on the relative distribution of the timing of natural meno- pause by race/ethnicity.

The estimates for the race/ethnicity- specific hazard ratios did not change significantly from those shown for any of these different methods.


Another possible limitation of our data was our measure of body mass index.

Since we did not have access to body mass index as a time-dependent variable, we relied on body mass index at baseline as an approximation of relevant body mass index.

We find no conclusive prospective evidence in the literature for an independent effect of menopause on body mass index.

In fact, we consider this an interesting future research question.


However, there is evidence that weight in women increases with age (55).

Thus, the partic- ipants who enrolled at older ages (postmenopausal women) will have tended to have higher body mass indices than they had at the age of menopause.

For older women, body mass indices will have been overestimated in the model.

Measure- ment bias would be possible if, for example, older women, with overestimated body mass indices, also tended to report later menopause than younger women.

These women would then appear to have a higher body mass index and later menopause.

However, in a sensitivity analysis excluding women over age 60 years, we found no evidence of bias in race-specific estimates by age.


Use of the failure-time modeling approach to assess predictors of the timing of menopause in this large, multi- ethnic sample provided us with ample statistical power to detect small differences in the hazard ratios for timing of natural menopause between strata.

We were able to show a significant racial/ethnic difference in the timing of natu- ral menopause that was independent of adjustment for po- tential confounders, and we have provided confirmatory evidence for factors hypothesized to be associated with the timing of natural menopause that had heretofore re- mained controversial in the literature.

These findings sup- port the hypothesis that the timing of natural menopause is driven by a combination of genetic, reproductive, and life- style factors.


In the article recently published by Henderson et al. [ 1] from the Multiethnic Cohort Study, the authors reported significant race/ethnicity-specific hazard ratios for the timing of menopause.

Natural menopause occurred earlier among Latinas and later among Japanese-American women relative to non-Latina whites.

The authors further emphasized that these relations are suggestive of a heritable component in the timing of natural menopause.

They concluded by stating, ‘‘. . .

the timing of natural menopause is driven by a combination of genetic, reproductive, and lifestyle factors’’ [1].


This conclusion suggests that the analysis of these data provides some evidence to support the assertion that group difference in the timing of menopause is at least partially driven by genetic factors.

The authors reached this conclusion without stating how racial categories were assigned [2] and without collecting any genetic information.

Although the authors are diplomatic in the overall interpretation of their results, the reference to genetic factors in the concluding statement seems to stem solely from the fact that racial/ethnic groups are compared.

An assertion that racial/ethnic disparities in an outcome suggest genetic differences ignores the complex social context experienced by different racial/ethnic groups.

This tenuous link among genes, race/ethnicity, and health outcomes is often made in the epidemiologic literature without adequately considering other important social and environmental factors that differ between groups [3, 4].


The authors did describe an ancillary analysis in which educational attainment, as a surrogate for socioeconomic status, was included as a covariate, but this is obviously a very coarse measure of the many facets of social environment that may affect the outcome.

In fact, a prior study of factors influencing the age of menopause identified several additional social variables, such as marital status and employment, which played an important role in predicting menopause onset [5].

This previous study also reported associations between race/ethnicity and onset of menopause, but it did not suggest a genetic basis for those differences [5].

In short, the use of race/ethnicity as a proxy for genetic differences in large, heterogeneous populations is unwarranted; drawing conclusions about the role of genetics in biologic processes requires the collection of genetic data.


We thank Mumford and Hasan [1] for their interest in our work [2] and agree with them that racial/ethnic variations do not necessarily imply genetic differences.

In reaching the conclusion that our results support the hypothesis that the timing of natural menopause is driven by a combination of genetic, reproductive, and lifestyle factors, we had in mind the fact that our findings are in line with a growing literature supporting the hypothesis that age at natural menopause is a highly heritable trait [3-9].

We also agree with the need to follow up these findings by searching for specific genetic variants that might contribute to the "genetic" component of age at natural menopause.

Indeed, we are currently engaged in developing candidate gene association studies of age at natural menopause and hope to identify new candidate loci through examination of data from genome-wide association studies, which could then be examined within and across racial/ethnic groups.


The claim that a fifth generation of revolutionary theory has not only already arisen, but has already outlived its purpose is a monumentally bold one.

Despite containing many astute observations, Jaime Allinson's (2019) recent argument to this effect does not adequately support such a claim.

Instead, it mostly targets valid criticisms against newer participants in a prior generation of revolutionary theory, whose analyses are not manifestly different from those we have seen in the past.

In the process of making his argument, Allinson fatally conflates these fourth-generation theories with his proposed new generation.

Despite this crucial flaw, Allinson's corollary argument- that revolutionary theory needs to move on from its present theoretical fixations- is still highly compelling and well supported.


Allinson (2019:143) is keen to impress that his proposed new generation is chiefly distinguished by having incorrectly identified the 2011 Arab Revolts as "a new object of study- that of non-violent, political revolutions." I would contend that such an object of study is precisely the domain of revolutionary theory's fourth generation, which cut its teeth on the analysis of the array of post-Soviet cases in which "there was no need for the revolutionary leaders taking power in the capital to spread their revolution by force," (Goldstone, 2001: 143).

The continuity between this perspective and more recent revolutionary theory is striking and explicit.

Only a few years ago, George Lawson (2015: 466) remarked that the Arab Revolts "share a familiar revolutionary heritage… in terms of wider currents of revolutionary theory," noting that they "sit largely within the framework established by the 1989 negotiated revolutions that ousted state socialism in Central and Eastern Europe." A similar continuity is seen in the texts Allinson recruits for his proposed fifth generation.

Indeed, Allinson notes that Bayat's (2017) analysis in Revolutions without Revolutionaries considers the Arab revolutions to be 'refolutions'.

This term is in fact derived from analyses of the post-Soviet revolutionary wave, in which the revolutionary ideal- tarred by the brush of Communist rule- was considered so politically toxic that the very concept of revolution was either side-lined or consciously rejected during the processes of regime-overthrow and reconstruction (Garton Ash, 1989).

If we are to take Ritter (2015), Bayat (2017) and Della Porta's (2016) objects of study to be "non-violent, political revolutions," as Allinson proposes, then they are most certainly engaged in fourth-generation revolutionary analysis.


Nonetheless, Allinson is certainly correct to suspect that our object of study has changed, and he is right to identify the particular importance of the events of 2011 for future revolutionary theory.

The Arab Spring was not only a new 'revolutionary wave', but was also emblematic of a distinctively different generation of revolutions.

The remarkable subsidence of revolutionary movements in the revolts which characterised the 2011 revolutions has shown, in stark terms, the poverty of existing theoretical perspectives.

Who would have thought, following the example set by the 1989 revolutions and the subsequent Colour Revolutions, that the next revolutionary wave would be carried through by a suite of fleeting revolutionaries who neither knew who their 'leaders' were, nor, in fact, whether they had any?


Many of today's revolutions neither resemble the classical revolutions of the past, nor those of the non- violent post-Soviet wave.

They are, as Allinson (2019:148) rightly notes, often "restricted to the momentary," easily crushed, and particularly vulnerable to counter-revolution.

This, in many ways, is their identifying feature: while the past generation of revolutions were characterised by their non- violence, newer revolutions are characterised by their fragility (we could even collectively call them the 'fragile revolutions').

Some theorists have even deemed them so fragile as to reject their revolutionary prospects altogether.

The political theorist John Dunn, for example, contends that since 1989, all instances of so-called 'revolution' have simply been processes of 'regime collapse,' lacking the strong cast-list of professional revolutionaries required to carry out genuinely transformative change (Abrams & Dunn, 2017; Abrams, 2018).


Despite the importance of these observations, I would affirm that the character of revolutionary waves must be distinguished from generations of revolutionary theory.

While I agree with Allinson that our object of study has decidedly changed, I would also stress that our analytical framework is yet to develop in tandem: current analyses still broadly regard the most recent wave of revolutions as if they were simply failing to follow the marche générale of the post-Soviet revolts, rather than as characterised by their own distinctive paths and dynamics.

In this sense, a novel generation of revolutions is being parsed with an established generation of theory.


Indeed, when we examine the intellectual positions which Allinson ascribes to his candidate generation, it becomes quite clear that his proposed 'fifth-generation' analyses are in fact characterised by fourth- generation traits.

For example, Allinson (2019, 143) contends that his candidate generation has shifted its emphasis to consider "the relationship between intentions, behaviour and structure in revolutions." This outlook is strikingly similar to Foran's observation that "social structure itself must be studied….

by reference to intentional actions." ( 1993:10), and Goldstone's (2001:139) argument that, in addition to structure, revolutionary theory should "incorporate leadership, ideology, and processes of identification with revolutionary movements as key elements in the production of revolution." A similar challenge can be made to Allinson's (2019: 143) suggestion that his new generation of theorists are distinguished by no longer considering revolution to be "a discrete event, capable of being situated on a continuum between social and political change and correlated with the presence or absence of other pre-existing factor[s]." Allinson instead claims that they have opted for a relational approach to the phenomenon.

This is quite a peculiar claim, as the relational approach to which Allinson alludes was considered the defining leap made by "a new fourth generation of scholarship on revolutions and collective action," (Emirbayer & Goodwin 1996, 374) and it has proven to be an agenda to which fourth- generation theorists have consistently returned to over the past three decades (Emirbayer & Goodwin 1996; Parsa, 2000; Goodwin, 2001; Goldstone, 2004; Lawson, 2004, 2016, 2019).

Finally, Allinson (2019:143) makes the argument that his proposed new theoretical generation is distinguished from the past generation by its claim that "revolutions should be understood as processes"- a series of unfolding events- rather than "singular units that can be correlated with other phenomena." This is, again, a well-established fourth-generation perspective: emphasised in Goldstone's revolutionary theorising (2001:152, 2009); established as a cornerstone of the relational approach (Emirbayer, 1997: 281, 304, 309); developed considerably across Charles Tilly's (1978, 1995) life's work; and taking centre stage in Foran's (2005) analysis of 'Third World Revolutions'.

It has been most recently returned to by Lawson (2016) and Ritter (2015) as a direct extension of this legacy.


Part of the reason that Allinson may have been tempted to declare more recent work part of a new, fifth generation is the disparity between what fourth-generation theorists have aspired to achieve, and what they have actually accomplished.

While fourth-generation theory has maintained a relatively consistent overall ontological and epistemological aspiration, its analytical contents are much more varied.

In fact, in contrast to prior generations, the fourth generation of revolutionary theory is a decidedly troubled one.

Despite featuring a plethora of insightful and highly interesting studies, it has ultimately failed to deliver on the early overall promises made by its proponents (Foran, 1993; Goldstone, 2001).

More than a quarter of a century since its inception, the desire to move on seems entirely reasonable.

There are, I argue, three principal obstacles to fourth-generation progress: the overambitious attempt to replace theorising with modelling; the related desire to cover too many variables at once; and the field's displacement by overlapping disciplines.


Fourth-generation revolutionary theory has been characterised by a variety of notable issues which present quite regularly in the associated literature.

The most central of these is the aim of fourth- generation theorists to simultaneously reject bold theorising in favour of iterative work, while also aspiring to build overarching models applicable to the total variety of revolutions across time and space.

When John Foran (1993:16) first heralded the prospects of a new, 'fourth' generation of revolutionary theory, he called for the replacement of grand theory with 'conjunctural modelling', through which periodic, careful case studies would gradually refine overall models of revolution, characterised by multiple facets and variables.

Foran's intention was to pioneer a turn away from mono-causal master- theories in favour of "models more complex and multicausal than the often one-sided arguments" seen in prior work.

In his manifesto for revolutionary theory's fourth generation, Jack Goldstone (2001: 144,172) espoused similar ambitions, declaring that "a full understanding of revolutions must take account of the plasticity of elite and popular alignments, of the processes of revolutionary mobilization and leadership, and of the variable goals and outcomes of revolutionary actors and events." He also declared that "it will treat stability as problematic and focus on the conditions that sustain regimes" while also leaving "a prominent role for issues of identity and ideology, gender, networks and leadership."


Foran and Goldstone's early aspirations for the fourth generation were certainly ambitious. They had called for the wholesale rejection of traditional theorising in favour of a new model-centric approach.

This new approach- were it to succeed- should yield nothing short of a predictive model of revolutions, applicable to an ever increasing historical and geographical variety of cases.

To these theorists' credit, both engaged in concerted attempts to build such a model for some time, before moving on to other projects (Foran, 2005; Goldstone, 1991; 1995).

While Foran and Goldstone's aspirations went on to shape the trajectory of the fourth generation, other fourth-generation theorists expressed substantial concern about this theoretical course of action.

For example, Emirbayer and Goodwin (1996: 360) took a particularly scathing line of critique against Goldstone's (1995) own model, which was supposed to "successfully predict, at least in principle, any and all revolutions." Crushingly, they lambasted the model for ignoring agency, psychology, emotional commitments, culture and politics.

They argued that, under Goldstone's model, "an outside observer need know nothing about a society's cultural systems or extant political ideologies in order to predict whether or not a revolution will occur there…[and] merely scour the local landscape for palpable signs of state crisis, elite conflict, and the possibility of popular protest," (Emirbayer & Goodwin, 1996: 361).


The daunting task of fulfilling Foran and Goldstone's aspirations has invited a peculiar tendency towards introspection among subsequent fourth-generation theorists, making it the most self-monitored generation of theory in the academic study of revolution.

1 This is at least in part a consequence of the coincidence of the idea of theoretical generations with the emergence of a self-consciously 'fourth' generation, but also reflective of the recognisable difficulty of achieving the aims set out for it (Lawson, 2016).

Indeed, many of those studying revolution have declined to engage in such a task, and have instead engaged in more atomistic analyses led by a smaller number of empirical cases, often discursively disconnected from one-another, and theoretically fractured (Beck, 2018).

This process has ushered in an era of fragmented analyses which, though highly worthwhile in their own right, have done little to advance the agenda of fourth-generation scholarship as a whole.


Despite its decline, a recent coalition of scholars have made some praiseworthy attempts to provide life- support to the otherwise faltering fourth generation.

Some, such as Colin Beck (2014), have attempted to move away from classical conjunctural modelling in favour of the development of a multi- dimensional meta-framework.

Others, such as Daniel Ritter (2015) have attempted to focus on the processual and international dynamics of fourth-generation theory.

What is common to both Ritter and Beck's approaches is that they refrain from making naturalistic, predictive claims beyond the realms of the cases they examine, in subtle rejection of the conjunctural approach.

Ritter (2015:223) is especially doubtful of the enduring nature of his finding that the success rates of predominantly non-violent and unarmed revolutions have been strengthened by a liberal world order.

He instead anticipates that the international pendulum may "swing back and make violent struggle against authoritarian states once more the revolutionary's strategy of choice." 2 Still others, such as George Lawson (2016) have attempted to usefully redirect early aspirations in an effort to get the fourth generation back on track, all while expressing a degree of scepticism as to the prospects of the overall project.

Nonetheless, amidst their admiration for the landmark theorists of the fourth generation, reading the work of this newer cohort belies a certain sense of discomfort with their predecessors' endeavours, which I suspect will eventually lead to their breaking with the fourth generation project.


Despite the ground-breaking work of its early theorists (Foran, 1993; Goldstone, 2001), there was, in my view, something mistaken in the fourth generation's attempt to reject bold theory.

This move was in part justified by the notion that past bold theoretical endeavours were somehow irreconcilable and exclusionary, each seeking to promote their own idealised universal cause (Foran, 1993: 16-17 Goldstone, 1980, 2001:171-172).

To the contrary, prior to the advent of fourth generation theory, the 'bold theorists' such as Skocpol (1979), Gurr (1970), Tilly (1978) and Trimberger (1978), consistently emphasised the complexity and contingency of the revolutionary phenomena they studied.


These theorists often sought to argue in favour of the primacy of one factor or another, but did so on the basis of an assumption that other variables also possessed substantial casual force.

Their efforts were more often corrective and exploratory than they were imperialistic.

Skocpol sought to re-centre attention on the State, which she felt had been sorely neglected.

Gurr sought to reassert the primacy of psychological factors, which he rightly observed were lacking in the analysis of revolution.

Tilly sought to draw attention to longer-running political processes, and Trimberger sought to illustrate the important roles played by revolutionary elites.


This is to say that these bold theorists engaged in in-depth investigations of a limited number of variables so as to shed light upon the complex relationships between that variable and revolution's other dimensions.

3 This kind of analytical depth has been comparatively neglected in the bulk of fourth generation theory which, in its efforts to account for an exhaustive list of variables, has all too often lost sight of the logic of their operation.


Co-occurring with the rejection of bold theory, was an ongoing shift in the structure of revolutionary inquiry, characterised by an analytical bias towards geographically and temporally homogenous cases (Beck, 2018), and a corresponding rejection of difference-based comparison by revolutionary analysts.

This had a deleterious effect on the advancement of the very agenda to which fourth-generation theorists aspired, producing- as Beck puts it in his (2018) review of the field- "the conditions under which knowledge accumulation slows." This shift has played a serious role in dampening the field's overall theoretical progress.

Because of the sheer variability of revolutionary phenomena, theoretical development must be situated in the analysis of fundamentally different cases, rather than a suite of highly similar ones.

If an idea is borne out across space, culture and time, then it may well be common to a great many revolutions.

The same cannot be said for something identified amongst a narrow set of historically, geographically or culturally delimited cases.

While, in principle, similar cases can yield theoretical benefits where only a very small and strictly controlled set of variables meaningfully differ between them, in practice, this situation essentially never occurs, even between cases which are as tightly geographically and historically delimited as possible.


While internal maladies have played an important role in the disappointing progress of the fourth generation, its lack of clear advancement has also been a consequence of the displacement of revolutionary study by other, much more populous fields, most particularly the fields of Social Movement Studies and Democratisation.

While it is undeniable that both of these fields have produced highly worthwhile insights about certain elements of revolutions, they do not ultimately regard revolution as their object of study, but instead consider it as containing a sub-form of some other category of events.

In such fields, revolutionary processes are instead regarded as an instance of 'contentious politics'; revolutionary movements are considered 'revolutionary social movements', and 'revolutionary outcomes' are reconceived as cases of 'democratic transition'.


The entry of social movement studies into the domain traditionally occupied by revolutionary theory began as a series of modest observations that some of the features of revolutionary movements resemble those of social movements (e.g. Goldstone, 1998), and that revolutionary processes shared commonalities with the political processes seen in social movements (e.g. Tilly, 1995).

This convergence was unsurprising, as the two fields have always enjoyed a considerable overlap 5 , owing to the tendency of sociologists of revolution to occasionally moonlight as scholars of (or indeed participants in) social movements.

As time went on, even more ambitious attempts to fuse the two fields were made, and it was claimed that that revolutionary processes and social movements were in fact part of a single overarching category of phenomena known as "Contentious Politics" (McAdam, Tarrow & Tilly, 2001).

Captained by three highly experienced, world-leading scholars- Charles Tilly, Sidney Tarrow, and Doug McAdam- the 'Dynamics of Contention' (2001) project attempted to create a new field of study which paid careful attention to the relational dynamics, mechanisms, processes and episodes which recurred across a wide array of political phenomena, such as disaffiliated protests, elections, ethnic conflicts, civil wars, and terrorism.

Chief among the project's targets for agglomeration, however, was what its proponents perceived as "a largely separate specialty dedicated to the comparative study of revolution:" at that time the chief vehicle for fourth-generation revolutionary theory (McAdam and Tarrow, 2011: 2).


While McAdam, Tarrow and Tilly's desire for a relational approach mirrored many of the concerns of fourth-generation theorists, much of the work which the trio dedicated to the relational analysis of common mechanisms, episodes and processes occurring across political phenomena was not as warmly embraced as they had hoped.

While the project successfully expanded the territory of the social movement field to include revolutions and civil wars, its central attempt to encourage scholars to think about dynamic relational mechanisms rather than fixed variables was comparatively less successful (McAdam & Tarrow, 2011).

While the conceptual waters of revolutionary theory's fourth generation have been contested by efforts to reconceive revolutionary processes as a subcategory within social movement theory, efforts to analyse revolutionary outcomes as a subtype of democratisation have had similar effects.

Such tendencies have been evidenced in the attempts to recast the 1989 and 2011 revolutionary waves as democratisation attempts, rather than revolutionary cases (Huntingdon, 1991; Brown, 2013; Stepan & Linz, 2013).

This effort has proven more to the chagrin of fourth-generation theorists than had the Contentious Politics project, leading to allegations that "the link between democratisation and revolution [was] routinely abused by transitologists" (Lawson 2008, 157).


These shifts in the field have resulted in considerable ramifications for the cohesion of fourth-generation theory.

Casting an eye over the work published about recent revolutions leads one to realise that many such publications now couch their analyses not in terms of revolutionary theory, but in terms of either social movement or democratisation studies (e.g. Jumet, 2017; Stepan & Linz, 2013).

While there is much to praise about these two fields, and the considerable progress they have made while revolutionary theory has comparatively stalled, it cannot be denied that these fields pursue markedly different objects of analysis.

Revolutions are occasionally incident in democratisation processes, and they often feature social movements, but within the study of these two phenomena they are ultimately only fringe cases.

It is thus no surprise the knowledge produced from such approaches has tended to tell us much more about democratisation or social movements than it has revolution.


With the progressive displacement of revolutionary study by other bodies of theory, the field has borne witness to an increasing number of scholars who theorise revolution without engaging in self-conscious revolutionary theory.

Perhaps reflective of the comparative primacy of these approaches over traditional revolutionary theory is Allinson's desire to count Della Porta's (2016) Where Did the Revolution Go? Contentious Politics and the Quality of Democracy, within the bounds of his proposed new generation.

The book is instead a self-professed attempt to "read democratization through the lenses of social movement studies," (2016: 345).

Despite the merits of Della Porta's book (and there are many: particularly her concept of 'eventful democratisation'), it is inaccurate to assess the book as a work of revolutionary theory.

Indeed, Della Porta makes no claims to such an endeavour, and instead concludes the volume by specifying that her contribution was instead to identify "some mechanisms that convey the effects of social movements' participation in regime transition on some democratic qualities of the ensuing regime," (Della Porta, 2016: 345).


While questions about democratisation, social movements, and other facets of contentious politics assuredly remain important and relevant to the phenomenon of revolution, however broadly we cast our gaze around the periphery of revolutionary phenomena we must remember that the object of study around which revolutionary theory is situated is and remains revolution itself.


Rather than dismissing a fifth generation out of hand, it is fairer to say that revolutionary theory's fourth generation is decidedly imperilled: perhaps by its desire to cover too many variables, perhaps by its turn away from bold theorising, perhaps by its partial displacement by other fields, and perhaps by the passage of time.

Whether recent interventions will enable it to recover from this peril remains to be seen, but regardless of the success or failure of these efforts, the nascent seed of a fifth generation is already being sown.

John Foran (2003), a one time champion of fourth-generation theory has called for the field of revolutionary theory to more usefully orient itself towards the revolutions of the future.

Colin Beck (2018) has, through a series of incisive accounts and studies shown convincingly that present strategies of inquiry have stalled.

As Allinson (2019) notes, we already have a suite of cases which disrupt established understandings, and as Lawson (2016) has convincingly argued, revolutionary theory is in dire need of theoretical reorientation.


Efforts to sustain fourth-generation theory would be much better spent cultivating the germinal ideas and discomforts of the fifth generation yet to come.

This demands that we reward inventive scholarship, embrace novel projects and theories, and do away with ontological or methodological purism.

But, what might a forthcoming fifth generation look like? Perhaps this is beyond the scope of any of us to predict at present, but I should like to at least provide a sketch of the direction in which things may be going.

I have a number of suspicions as to where the nascent fifth generation will take us, chiefly informed by my interactions with fellow colleagues, graduate students, and those who we might cautiously call 'practitioners'.

In light of these exchanges, I am hopeful that we may well see a return to grander theorising than the kind seen in the fourth generation.

In order to advance past our field's current impasse, we need a return to the kinds of ambitious comparisons, and innovative, in-depth theoretical accounts which have consistently characterised landmark work on revolution.

Taken together, the past thirty years of scholarship have tended to show that concerns for multivariate breadth and processual partiality have been less conducive to scholarly progress than have past preferences for explanatory depth and empirical diversity.


As a relatively mature field, there is no reason that revolutionary theory cannot incorporate both kinds of analyses: in depth case studies and comparisons of differing cases to theorise the operation of important elements of revolution in a bold and compelling fashion, and larger scale meta-analyses to show how these elements interact with scientific precision.

Not only is the opportunity ripe to give some order to the diffuse and partial analyses of the fourth generation, but also to revisit and update the contributions of the prior three in view of a more expansive object of study, and a more assertive theoretical bent.

A crushing absence of difference-driven inquiry in past decades (Beck, 2018) has also left plenty of room for novel comparisons stretching across time, space, and culture, through which new insights might be achieved.


There are also arrays of unsolved problems and theoretical lacunae which are ripe for attack from a new generation of theorists.

It is certainly true, for example, that the coming generation of revolutionary theorists will need to account for the counter-revolutionary and authoritarian outcomes which arose from the 2011 revolts (Allinson, 2019).

As Foran (2003) has emphasised, both the ends and endings of revolutions are areas much neglected by present-generation scholars.

Revolutionary theorists have traditionally been very good at stating the relation between pre-revolutionary conditions and subsequent revolutionary challenges, and fourth-generation theorists have extended this analysis to the relation between revolutionary contexts and ongoing challenges elsewhere.

However, very little has been done to clearly link the shape of revolutionary challenges with subsequent post-revolutionary outcomes (be they positive or negative), while retaining a perspective that looks beyond organised movements or static state boundaries.


This is not the only context in which revolutionary theory will need to look beyond revolutionary movements in its unit of analysis.

Indeed, a fifth generation of revolutionary theory will need to look 'beyond the movement' in several other important ways if it is to capture the full variety of revolutionary phenomena.

Not least, we will need to look beyond the organised networks of revolutionary elites and their followers, and again consider the role of the masses: not as a disordered mob, but as an array of complex individuals responding to intense socio-political phenomena and drawing on a rich palette of imaginaries (Selbin, 2019).

As Beck (2011, 2015) has affirmed, we will also need to consider the role played by revolutions in transforming societies other than those in which they initially occur. And finally, I would contend that we will need to reassert the importance and veracity of decidedly revolutionary theorising, studying revolutions as socio-political events that are not always reducible to merely more extreme forms of social movements, processes of democratisation, or a subcategory of 'contentious politics'.


Finally, reflecting on the concerns of revolutionaries themselves, I sense that they hope- but do not expect- that the next generation of revolutionary theory will be more decidedly engaged with revolutionary practice.

Since the end of the Jacobin-Bolshevik revolutionary epoch (1789-1989), scholars have become all the more content to regard revolutions with dispassionate interest, watching these bloody, brutal and dramatic social processes take place with a steely gaze before integrating them into their models or dataset for 'productive' analysis.

But revolutions are not toys, and they are not scholarly miscellanea.

They are the bloodied, broken corpus of the body politic in conflict with itself.

As such, we should aspire that future revolutionary theory might go some way toward ensuring that these processes result in collective emancipation, rather than merciless annihilation.


A recent exchange between Allinson (2019) and Abrams (2019) on the current state of revolution theory rests on the assumption that the generational, backward-looking view of revolution studies is also a fruitful way of thinking of the field’s present and future.

We argue, in contrast, that while a generational approach has important benefits, it also contains shortcomings that may lead the future of revolution studies in less fruitful directions.

We examine where an overreliance on generational thinking has led us, and provide an exploratory sketch of how we can begin to move beyond generational thinking and imagine a new future for the study of revolution.

It is with great interest that we read the exchange between Jamie Allinson (2019) and Benjamin Abrams (2019) on the state of revolution theory in the social sciences, and not just because our works are among those that represent, for Allinson, a failed fifth generation or, for Abrams, a self-monitored fourth generation.

We do not seek to quibble with their insights and critiques.

Rather, we propose that their debate has taken place on false premises.

Jack Goldstone’s (1982, 2001) formulation of generations of revolution theory has been an invaluable orientating tool for virtually every student that has entered the field over the past four decades.

However, it has also led to the establishment of an overly neat and consolidated perception of the field.

Goldstone’s historical-theoretical review of the literature has become reified as the actual history of the subfield in a way that at times limits our ability to assess what has been discovered about revolutions and, more crucially, prevents us from seeing where the path ahead lies by locking us into the idea that the future of revolution too will be constructed along generational lines.

Hence, we believe that Goldstone’s generational framework has been taken out of context and transformed beyond its original aim by subsequent generational reviews of the field.

Rather than being a tool for understanding and consolidating past gains, it has become the only way authors believe they can structure the field’s present and future.

By way of critique of the Allinson and Abrams exchange, we propose to take the field beyond generational thinking.

We argue that a persistent focus on generations is misguided as debates in revolution research actually occur laterally among contemporaneous studies of revolution, rather than sequentially between reified paradigms.

This is partially a consequence of mistaking touchstone texts for generations of scholarship (see for instance Ritter’s (2015: 9-12) review of the literature, which Beck (2020) has thoroughly dismissed).

As such, we have lost sight of our accumulated knowledge over the last one hundred years.

In fact, the basic contours of what revolution scholars should study, how they should study it, and how it should be explained is largely settled.

Consequently, it is time to imagine a new future for the study of revolution.


While not the first article to seek to make sense of subfield (see for instance Stone 1966), no essay has had more impact on the way scholars think of the development of revolution theory than Goldstone’s (1980) overview of the early to mid-20th century.

Updated two decades later (Goldstone 2001), Goldstone proposes that the study of revolution has come in the form of generations, where a general understanding of what was to be explained was widely shared by scholars who had common methodological and theoretical approaches.

Goldstone identifies an early-20th century first generation, which he terms “the natural-history school” (Goldstone 1982: 189), that focused on the sequential progression of the revolutionary process in classic cases of revolution, such as France in 1789.

In response, a second generation of scholars sought to place revolutions in the field of collective political violence, focusing on more general theories that connect the individual, psychological causes of discontent with social unrest.

Since Goldstone’s initial formulation, this approach has become known as the generation of social and psychological strain theories.

The third generation, termed “the structural-theory school” (Goldstone 1982: 189), moved the problem towards understanding why some revolutionary episodes succeed and others fail.

This approach has become most associated with Theda Skocpol’s (1979) state breakdown theory to the extent that the two are largely synonymous.

Most recently, theories of revolution for the past 25 years have been seen as belonging to a fourth generation that has an epistemology of conjunctural causation, dynamic eventful analyses, and an ever-expanding universe of factors under consideration (see Lawson 2019).

It is here where Allinson (2019) and Abrams (2019) differ.

For Allinson, the fourth generation represents a return of agency-centered explanations that was eclipsed by a short-lived “fifth generation” examination of unarmed revolutions and changes to political regimes.

For Abrams, the current focus on revolutions like the Revolutions of 2011 is a continuity of fourth generation approaches, and thus a fifth generation is yet to develop.


A final consequence of generational thinking has been the rhetorical move, in literature reviews and theoretical frames, to suggest that a dramatic break with the old is required for something new to be learned.

Allinson’s (2019) critique is very much in this vein.

When we take this rhetoric seriously it is easy to conclude that there are no consistent findings within the study of revolution (see Kurzman 2004a). But, in fact, there are.

We do not seek to repeat a catalog of findings here as we have already done so elsewhere (see Beck 2017, 2020; Goldstone and Ritter 2018).

Rather, we suggest here that the central questions of the field that animated 20th century debate—what to study, how to study it, and how to theorize—mostly have been settled.

The first point of debate in the first half century of revolution theory was what the object of study should be.

On the one hand, revolutions could be taken to be only the cases of political and social change that were world historically important (Brinton 1938; Edwards 1927; Huntington 1968; Skocpol 1979).

On the other hand, revolution could be taken to be one form of contentious politics more broadly and placed alongside riots, social movements, terrorism, civil war, and so on (Gurr 1970; McAdam, Tarrow, and Tilly 2001; Smelser 1962; Tilly 1978).

After nearly a century of the social scientific study of revolution, such diametrical poles seem absurd.

No longer do scholars only study successful transformations of state and society. And no longer do scholars see revolution as on a continuum of the irrational exuberances of collective behavior.

Rather, revolutions are seen as a distinct process of collective action, where success and failure are outcomes to be explained rather than criteria for inclusion or exclusion in a study (e.g., Foran 2005; Goldstone 1991; Ritter 2015; Tilly 1993).

And avowed revolutionary movements do exist, but the various types of contention that can result in revolutionary challenges need to be explained (e.g., Beck 2015; Chenoweth and Stephan 2011; Goldstone and Ritter 2018).

In short, the object of study is clear to contemporary scholars: attempted and successful shifts in, at the very least, regimes or political structures that occur through irregular mass mobilization.

The second debate that animated prior scholarship was the method of study.

Should the scholar examine cases for particular historical knowledge (e.g., Kurzman 2004b; McAdam et al. 2001) or should they seek general laws of revolution (e.g., Gurr 1970; Huntington 1968)?

The epistemological debate here obscures what is essentially a methodological dispute.

On the one hand, some preferred historical case comparative modes of inquiry and others preferred cross-national statistical analysis.

Modern revolution studies, for the most part, does not make this false choice.

For instance, Goldstone (1991) and Gould (1995) have shown how careful historical analysis can be combined with innovative quantitative study to leverage the advantages of both approaches.

Even among recent statistical studies (e.g., Chenoweth and Stephan 2011; Kadivar 2018), case comparison is a common compliment to the average effects within a population.

This is not to say that all studies of revolution employ mixed methods, but rather that methodological approaches are not mutually exclusive.

Debates over method are thus of a time that is passed.

This, however, has not settled the larger epistemological question: what should theories of revolution focus on? This leads us to the third point of debate.

Finally, there can be disagreement over the core theoretical imagery of revolution studies.

On one hand, should revolution be understood as resulting from broad causal conditions (e.g., Foran 2005; Goldstone 1991; Skocpol 1979) or seen as a dynamic process (e.g., Ermakoff 2015; Kurzman 2004b; McAdam et al. 2001)?

In essence, this is an epistemological debate over the role of structure and agency in revolutions.

This debate is not settled, and we should not expect one subfield to solve the structure-agency problematic.

We suggest, however, that a feature of recent scholarship is to leverage both lines of thought.

For instance, both Lawson (2019) and Ritter (2015) combine a backdrop of causal conditions with an account of how particular cases of revolution unfolded in the streets.

Now it is possible to prefer structure, as does Ritter, or lean slightly more towards agency, as does Lawson, but it need not be to the exclusion of the other.

With time, we may in fact see that the advantage of the so-called fourth generation (Abrams 2019) or failed fifth generation (Allinson 2019) was to sidestep theoretical disagreement in favor of empirical work.

As with methodology, preference for particular causal imageries may just be an academic parlor game that has gotten in the way of knowledge accumulation (see Beck 2018).

Related to this final point, generational thinking constitutes a particular obstacle to the study of revolutions, due to the fact that theorization has long been perceived as central to the subfield.

This has meant that reviews of the literature tend to obscure the distinction between empirical findings and theoretical contributions.

Put differently, what we think we know about revolutions has historically been framed as pre-packaged theoretical solutions advanced by individual authors to revolution-related puzzles that “fit” with other such individual insights produced at a similar point in time, rather than empirical insights that can serve as inspiration to and be adapted by other scholars.

By suggesting we have not achieved a substantial advance until some consensus on a new generation emerges, we risk losing sight of important, untheorized empirical insights that might quite plausibly give rise to future theoretical breakthroughs.

In sum, if we free ourselves of the metaphor of generations of revolution theory, then we are able to see not only the continuity of debates over the decades but their (mostly) successful resolutions.

Contemporary revolution studies have a consensual object of study, a pluralistic methodology, and a potentially fruitful empirical core.

This success, and we are comfortable calling the last century of the social science of revolution successful, should not be obscured by a rhetoric emphasizing the need to throw out the old and remake the field anew.

If there is something to generational thinking, it is only that: calls to do away with prior scholarship seem to re-occur every 20 years or so.

Our point thus far has been that the metaphor of generations of revolution theory creates a false premise on which we debate progress or the lack thereof.

We see previous work as caricatures rather than as products of a larger scholarly conversation.

And we lose track of what has been settled and what remains to be explained. If we free ourselves from wondering what the fourth generation was or is, and what the fifth generation is or will be, we can begin to chart a more fruitful future for the study of revolution.

What any field needs, and what revolution theory currently requires, is novelty.

Rather than musty generational debates, we need creativity in theory, empirics, and resulting implications.

In ideal-typical terms, there are two dimensions to any study of revolution.

On the one hand, research can be theoretically-oriented—focused on developing new understandings—or empirically-oriented—focused on explaining substantive phenomena.

On the other hand, research can have universal implications for understanding revolution or more specific, particularistic claims about certain cases.

Figure 1 presents these dimensions as a two-by-two table, highlighting four potential sources of novelty in the study of revolution with examples from the last two decades of research.


First, there is novelty that results from theory-oriented research that has universal ambitions.

Work here tends towards theoretical parsimony combined with the examination of well-known cases.

For instance, Foran (2005) argues that recent Third World revolutions can be explained by the combination of five factors—dependent development, exclusionary regimes, a culture of opposition, economic downturns, and a world systemic opening.

In another example, Lawson (2019) searches for recurrent mechanisms across executed and attempted cases of revolution ranging from the early modern world to the present.

He concludes that there are eight processes that occur across revolutions—inter-social relations, loyalty or disloyalty of coercive forces, regime type, state stability, innovative oppositional strategy, factionalism among revolutionaries, continued contestation after the fall of a regime, and limited economic gains for the post-revolutionary state.

Both of these works share the theoretical ambition to explain revolutions generally and the empirical incorporation of many cases.

As such, they generate novel insight into the patterns of revolutions and their outcomes.

At the opposite pole is research that is empirically-oriented explanation of particular instances of revolution.

Here the objective is the incorporation of new cases into the revolution literature, whether from current events or the successful recovering of past history.

For instance, as the Arab Revolutions of 2011 spread, scholars took voluminous notice of the cases without necessarily making broad claims about the nature of revolution.

For example, Ketchley (2017) examines Egypt in 2011 and afterwards using well-known tools of analysis to explain why and how protestors were able to oust Mubarak and unable to consolidate their gains.

Novelty here comes from the success of affirming the membership of an event in the fold of revolution studies.

The approach contributes to the field by expanding the case universe.


Third, other work seeks to explain new phenomenon rather than cases, with more universal import.

A primary example of this approach is the civil resistance literature.

For instance, Chenoweth and Stephan (2011) build on this approach to establish through statistical analysis and case examination that in the modern world unarmed strategies of resistance tend to have more success than armed ones.

The goal for works of this type is to ask a new question—what are the causes and consequences of a relatively unrecognized aspect of revolution?—and offer answers that have implications beyond the cases at hand.

Novelty thus comes from the examination of new dimensions of revolutions.

Finally, a fourth source of novelty is to create entirely new ways of understanding that focuses on particular instances of revolution.

Here, the goal is usually not abstract parsimony but theoretical richness.

Two recent examples of this approach are Selbin’s (2010) consideration of the role of stories and narrative for revolutionary participants and Ermakoff’s (2015) appraisal of how contingent decisions by individuals can radically change the direction of revolutionary events.

Both consider the particulars of their examples, but provide new theoretical lenses for the field.

Notably, they both also suggest different methodologies than are commonly used—oral history and decision-making trees.

Novelty, here, thus comes from theoretical and methodological innovation.

Sometimes a field is moved forward by parsimony, sometimes by complexity.

Sometimes it moves forward through events, sometimes through patterns.

Thus, all of these approaches to revolution should be encouraged and embraced.


Charles Tilly famously told his graduate students that there are three types of academic work: joining an ongoing conversation, changing the direction of a conversation, and starting a new conversation.

The first is lower risk, and lower reward.

Work on revolutions that explicitly places itself in generational debates is of this ilk.

The second is medium-risk and medium-reward as it may or may not shift a debate.

New abstract models of revolutions and examination of new cases are typical of this approach as they build upon the old rather than create anew.

Finally, the third sort of conversation is high-risk and high-reward as it can spur new paradigms.

Research on new phenomena and new theoretical lenses are of this sort. On one hand, scholars of unarmed resistance have had great success at creating an entirely new conversation at the intersection of sociology, political science, and international relations.

The flurry of work that Allinson sees as a fifth generation is proof of that.

On the other hand, Selbin and Ermakoff have challenged us all to think of revolution differently.

The last century of revolution studies certainly has been a very long conversation.

As such, it is unsurprising that we often repeat ourselves. But with a more accurate memory of what has been said by whom, to whom, and for which purpose, perhaps we can stop arguing over generations and resume debating ideas and phenomena.

Only this way will we push our dialogue forward for another hundred years.


Revolutionary theorists are currently immersed in a critical debate about the future of the field.

Allinson has argued that a fifth generation of revolutionary theory has passed us by without our noticing, while I have contended that it is revolutionary theory's fourth generation that is decidedly imperilled.

Ritter and Beck contend that we should reject the very idea of theoretical ‘generations’, and instead think of progress in revolutionary theory as a series of ongoing and settled debates about certain key topics.

The pair contend that revolutionary theory has reached a consensus on two core debates: defining our object of study and determining appropriate methods.

Contrary to this position, I argue that while there is much to praise about rejecting generational imagery, doing so necessarily entails that we also critique the self‐proclaimed ‘fourth generation' with which such imagery is intertwined.

Furthermore, I argue that there does not yet exist consensus among revolutionary theorists about a single definition of revolution, or on the question of which methods to use.

Finally, I call for a regeneration of revolutionary theory which moves genuinely beyond the generational mythologies of the past.


Over the course of the past decade, the intellectual project by the name of ‘Fourth Generation Revolutionary Theory' has been principally sustained by a trio of scholars.

George Lawson, Colin Beck, and Daniel Ritter, the collective heirs to a project primarily initiated by John Foran (1993) and Jack Goldstone (2001) some decades earlier.

Breaking with Lawson (2016 114; 2019), who has recently called for scholars to “fulfil the promise of fourth‐generation approaches to revolution,” Beck and Ritter (2021) now conversely argue that we should not only dispense with the notion of fourth generation revolutionary theory, but also the premise on which the self‐proclaimed ‘Fourth Generation' was built: the story of the prior three.

Though it once constituted the cutting‐edge of revolution studies, there is by now much to welcome in moving away from the embattled fourth generation endeavour.

I have previously written that Ritter and Beck's “attempts to provide life‐support to the otherwise faltering fourth generation” might “eventually lead to their breaking with the fourth generation project,” (Abrams, 2019, p. 381).

This eventuality has now come to pass, and the self‐identified ‘Fourth Generation’ has in essence passed with it.

Moving beyond such an overly elongated period of scholarly hand‐wringing has the potential to usher in a much needed rejuvenation and regeneration of revolutionary theory.

But as we put the fourth generation project to rest, what can we do to ensure a more fruitful future for our field? In what follows, I welcome the rejection of the generational paradigm, and the fourth generation project to which it is inseparably linked.

I nevertheless contend that the ‘fourth generation of revolutionary theory' can still be meaningfully distinguished from the narrative history of a prior three.

Rather than serving as a conceptual shorthand for a particular period of revolutionary study, the ‘fourth generation’ was instead a self‐conscious programme for the study of revolution, advanced by a series of distinct actors.

This, in turn, renders critique and discussion of the fourth generation project a meaningful exercise.

I also critique the argument advanced by Beck and Ritter (2021) that – in place of the generational narrative – we should instead depict revolutionary theory as having reached a consensus on two core debates: defining our object of study and determining appropriate methods.

I argue that there is neither consensus about a single definition of revolution, nor on the question of which methods to use.


Breaking with the fourth generation paradigm to which they once ascribed, Colin Beck and Daniel Ritter's recent article, Thinking Beyond Generations: On the Future of Revolution Theory, has made a convincing argument that progress in the field of revolutionary theory would be best served by discarding the concept of theoretical generations altogether.

This is a notable break from their past approach to the subject.

Beck, for example, once considered it “clear” that “the social science of revolution has undergone notable generational shifts in theory and the phenomenon of study,” (Beck, 2017, p. 170) Ritter similarly explicitly deployed a generational account of revolutionary theory in his landmark volume on international politics and unarmed revolution, The Iron Cage of Liberalism, (2015 9‐10).

While Ritter and Beck were once counted among the fourth generation school, they now eschew such thinking and instead encourage us to instead think ‘beyond generations’.

In their article Ritter and Beck level a number of productive critiques against overreliance on the notion of theoretical generations.

They note that while there is certainly some utility in the generational framework, it is outweighed by the cognitive constraints it places on our understanding of the field, and the hidden knowledge obscured by generational thinking.

While it has long been acknowledged that “classification of theories by generation is problematic,” (Foran, 1993, p. 1), Beck and Ritter skilfully draw attention to the great many scholars whose work has been eclipsed by the generational imagery derived from Goldstone's reviews of the field, and highlight a variety of contemporary scholars whose analyses do not fit into the ‘fourth generation’ programme.

Their analysis clearly demonstrates that refusal to move beyond an overly strict conceptualisation of theoretical generations has had an unhelpful impact on our thinking to the extent that today “generational imagery has obscured as much as it has illuminated.” Fortunately, there are many useful alternatives to generational framings.

Foran (1993:1) once suggested that “the best alternative is to group… theories by theme or approach,” and Ritter and Beck make a good case for recasting the history of revolutionary theory's early development in terms of a series of scholarly debates.

We might also seek to reframe what we have called ‘generations’ as intellectual fashions, thereby preserving the observation of rising scholarly tendencies over time without subsuming pathbreaking work into a single rubric.

There are many compelling reasons to explore at least one of these alternative frameworks where the history of revolutionary theory is concerned.


Despite the usefulness of their central proposition, I would certainly challenge Beck and Ritter's claim that the debate between myself and Allinson – about the fourth generation and its potential successors – “has taken place on false premises.” Regardless of the veracity of past reviews of the literature, it is impossible to deny the existence of an intellectual project by the name of ‘fourth generation revolutionary theory.

’ It is precisely this intellectual project – and the potential for a break with it – that formed the central topic of our debate.

What have been commonly referred to as the first three generations of revolutionary theory were in fact a set of historical cases drawn‐up by Goldstone (1980; 2001) in order to review the general changes in discourse between key scholars over various prominent topics in revolutionary theory.

Unlike the facets of past literature reviews that constitute ‘Generations’ 1‐3, the self‐professed ‘Fourth Generation of Revolutionary Theory’ was not an attempt to categorize the past, but an ambitious attempt to propose a new future.

This was a distinctive intellectual project in which an array of academics participated, and others declined to.

It was actively and self‐consciously cultivated and maintained by a network of scholars (e.g. Beck, 2017; Emirbayer & Goodwin, 1996; Foran, 1993; Goldstone, 2001; Lawson, 2016, 2019; Ritter, 2015), having been introduced in Foran (1993), Emirbayer and Goodwin (1996) and Goldstone's (2001) various manifestos for a fourth generation and continued in Lawson's (2016) more recent intervention on the subject.

A key part of the fourth generation's intellectual programme was the self‐identification of its participants as members of a new ‘fourth’ generation of revolutionary theorists.

This was grounded in a generational teleology that presented the self‐proclaimed ‘Fourth Generation' as the summation of three past ones identified by Goldstone (1980).

By its own reckoning, the fourth generation project was to be a coming‐of‐age for the study of revolution, after which scholars would overcome the tendency for single‐factor analysis, and instead adopt a holistic, conjunctural approach.

It was at once “a self‐conscious canon,” and “a project to be realized” (Lawson, 2016, p. 107).