The paleontologist and evolutionary biologist Stephen Jay Gould, one of America's finest scientific communicators (Allmon, Kelley and Ross 2009), made fundamental contributions to evolutionary biology, not least through his development of the ideas of “punctuated evolution” (Gould 2002, 759−61; Eldredge 2013) and evolutionary “spandrels” (Müller 2013), and his use of the decidedly 1990s metaphor of “rewinding the tape” of evolution to highlight the importance of contingency within the evolutionary process (Beatty 2006; Turner 2011). His reputation as a scientific educationalist is based on his masterpiece The Structure of Evolutionary Theory (Ayala 2005). Gould is, however, probably best known to readers of this journal for his notion of “Nonoverlapping Magisteria (NOMA)” (Gould 1997; Gould 1998, 269−83), particularly as this is set out in his book Rocks of Ages (Gould 1999).

Gould was not a religious person, and self‐defined as an “agnostic in the wise sense of T. H. Huxley” (Gould 1999, 8−9). Yet he considered the interaction of science and the humanities in general, and religion in particular, to be a topic of significant cultural concern, better framed in terms of conversation rather than antagonism (Gould and Purcell 2000). In the late 1990s, Gould argued that science and religion represent separate and nonconflicting realms or “domains of authority (magisteria),” suggesting that he found this idea in Pope Pius XII's encyclical Humani Generis (Gould 1997). For Gould, science deals with the empirical realm, and develops theories to explain the observed facts of nature; religion deals with the realms of ultimate meaning and value. Although both these magisteria are essential for human fulfillment, they represent different outcomes of different rational processes. Gould's early formulation of this principle, which is best seen in Rocks of Ages (1999), takes the following form:

I do not see how science and religion could be unified, or even synthesized, under any common scheme of explanation or analysis; but I also do not understand why the two enterprises should experience any conflict. Science tries to document the factual character of the natural world, and to develop theories that coordinate and explain these facts. Religion, on the other hand, operates in the equally important, but utterly different, realm of human purposes, meanings, and values—subjects that the factual domain of science might illuminate, but can never resolve. (Gould 1999, 4; cf. Gould 2003, 87)

Gould's concept of “NOMA,” generally interpreted as asserting the “independence” of science and religion (Barbour 2000, 95−97, 99−100), has been criticized as an impediment to progress in the field of science and religion. Two representative criticisms should be noted. John Polkinghorne suggested that this view was “neither experientially supported nor rationally justifiable.” For Polkinghorne, Gould offers a “rationally unsupportable” account of the relation of science and religion, which is rendered problematic through even the “most cursory acquaintance with the intellectual history of the last four centuries,” which makes it quite clear that they cannot “be isolated from each other in watertight compartments” (Polkinghorne 2005, 44). The philosopher John Caiazza considered it to represent an unwelcome, if unintended, reprise of the medieval philosopher Siger of Brabant's problematic notion of a “double truth” (Caiazza 2005, 11−12), which resolves contradictions between intellectual domains such as theology and philosophy by treating them as “contrary truths,” each of which is valid within its own domain. Although recent scholarship has raised significant doubts about whether Siger of Brabant explicitly held such views (Giletti 2021), Caiazza's concern about the intellectual isolationism that Gould's approach appears to entail remains significant.

Yet these representative expressions of concern relate to Gould's formulation of NOMA in the late 1990s. This article argues that Gould's critical reading of Edward O. Wilson's Consilience (1998) appears to have prompted him to modify his earlier approach. In The Hedgehog, the Fox, and the Magister's Pox (2003), published after his death, Gould offers a more nuanced and expanded account of his earlier approach, which represents his most considered assessment of the relation of the sciences and humanities (York and Clark 2005, 290−93), reframing the notion of “NOMA” in more positive terms as a “consilience of equal regard.” This article will consider this final articulation of his position, exploring how it emerged, how it meets some of the criticisms directed against his earlier position, and noting some unresolved issues that appear to require further engagement.

What is “Consilience”?

The term “consilience” was first introduced by the British empirical philosopher William Whewell (1794−1866) in the 1840s as a result of his dissatisfaction with Aristotle's account of how it was possible to proceed from observations to general principles. Whewell's main criticism of Aristotle was that he failed to give adequate attention to the need to introduce new ideas or concepts, such as some kind of “organizing principle,” which was integral to the process of scientific explanation (Niiniluoto 1994, 52−54). Whewell invented the term consilience, drawing on a Latin root meaning “jumping together” to refer to this process of leaping from an assembly of observations to their explanation through some “coordinating principle,” which was not strictly and unambiguously disclosed by those individual observations themselves. Whewell envisaged an imaginative act of leaping beyond what the observations disclosed, and using this resulting interpretative framework to coordinate those observations. The degree of coordination—or “colligation”—that this framework afforded could be seen as an indication of its reliability (Cowles 2016; Dethier 2018).

So, why did Gould become interested in the relatively obscure British philosopher William Whewell, and the neglected notion of consilience? The answer lies in the first of three mottos that Charles Darwin included on the title page of his Origin of Species (1859). Darwin here reproduced a brief passage from Whewell, stressing the importance of establishing general laws underlying the phenomena of the material. World. “But with regard to the material world, we can at least go so far as this—we can perceive that events are brought about not by insulated interpositions of Divine power, exerted in each particular case, but by the establishment of general laws” (Darwin 1859). This passage, taken from Whewell's influential “Bridgewater Treatise” of 1834 (Whewell 1834, 356; cf. Topham 2010), hints at the importance of Whewell's empirical philosophy to Darwin's own intellectual development.

In an article of 1975, Michael Ruse argued that Whewell's notion of the consilience of inductions was of decisive importance in enabling Darwin's appreciation of the evidential virtues of his theory of natural selection from 1838 onward (Ruse 1975; cf. Ruse 1979). In a careful 1986 study of Darwin's historical methodology, which draws on Ruse's analysis, Gould offered an insightful account of how Darwin was able to weave together seemingly disparate and disconnected biological arguments to yield a coherent theory—despite the fact that this evidence did not, and could not, prove his theory—as writers such as Thomas H. Huxley hoped it would, through some dramatic and conclusive experiment. Gould summarizes Darwin's methodological insight incisively using Whewell's terminology: “Huxley sought the elusive crucial experiment; Darwin strove for attainable consilience” (Gould 1986, 65; cf. Gould 2002, 108−11).

Gould's appreciation of Whewell's importance in helping Darwin develop his theory of natural selection is clearly grounded in a good understanding of Whewell's intellectual method, which is analyzed in some detail in The Hedgehog, the Fox, and the Magister's Pox (2003). As Gould's editor Leslie Meredith notes, this work, which was published after Gould's death, is unusual. Most of Gould's popular works took the form of collections of already‐published essays (Gould 2003, xi); this late book, however, is an original work, devoting more than 100 pages to a detailed account of Whewell's theory of consilience, and a critique of Wilson's use of this concept in his Consilience: The Unity of Knowledge (1998).

Probably reflecting the emphasis placed on the notion in Wilson's Consilience, the term “consilience” has now come back into fashion after an extended period of neglect as a way of stimulating and informing discussions of the relation of the natural sciences and the humanities (Carbonell 2011; Di Rocco 2018). In what follows, we shall consider Wilson's Consilience, both as a work of importance in itself (Wilson 1998a), but also a stimulus to Gould's further reflections on the relation of the natural sciences and the humanities in general, and religion in particular.

E. O. Wilson on Consilience

Although Wilson is today better known for his abandonment of “kin selection,” a theory that he helped popularize during the 1970s (Gibson 2013), he attracted much attention around the turn of the century for his unificationist approach to knowledge, set out in his 1998 work Consilience. “We are drowning in information, while starving for wisdom. The world henceforth will be run by synthesizers, people able to put together the right information at the right time, think critically about it, and make important choices wisely” (Wilson, 1998a, 294). This emphasis on “synthesizers” can be seen as the culmination of the unificationist program that he initiated 20 years earlier with the publication of his Sociobiology (Carbonell 2011, 346−46). Wilson presents the idea of consilience in this 1998 manifesto for the unification of human knowledge in terms of the “basic scientific principle of cross‐disciplinary consistency” (Lo 2013, 270).

Wilson notes the growing trend to regard the natural sciences, social sciences, and humanities as separated “by an epistemological discontinuity, in particular by possession of different categories of truth, autonomous ways of knowing, and languages largely untranslatable into those of the natural sciences” (Wilson 1998b, 17). Gould also recognizes this concern, and shares Wilson's concern to counter the trend toward intellectual fragmentation. Yet their strategies for achieving this goal, and their respective understandings of the nature of consilience, diverge significantly.

Wilson's formulation of the “unity of knowledge” in terms of “universal consilience” sets out an intellectual framework for holding together the plurality of insights that arise across the disciplines. Throughout his works, Wilson appears to exhibit “what might be called a general unification wish” evident in his “desire to produce order out of chaos” (Segerstrale 2006, 47).

In line with Wilson's earlier writings, this approach to the unification of human knowledge is based on a “metaphysical worldview” which privileges the scientific method over those of the humanities. Although Wilson intertwines the natural sciences, the social sciences, and the humanities in his notion of consilience, there is never any doubt about the dominant partner in this synthesis.

The central idea of the consilience world view is that all tangible phenomena, from the birth of stars to the workings of social institutions, are based on material processes that are ultimately reducible, however long and tortuous the sequences, to the laws of physics (Wilson 1998a, 291).

Wilson considers this a natural and reasonable consequence of the superior explanatory capacities of the natural sciences. For Wilson, consilience is ultimately a “metaphysical world view,” which is “allegiant to the habits of thought that have worked so well in exploring the material universe.” Although it “cannot be proved with logic from first principles or grounded in any definitive set of empirical tests,” it still claims to offer the best way of rationalizing the intellectual habits of the social sciences and humanities (Wilson 1998a, 9). Wilson himself concedes that such theories are “working hypotheses,” promissory notes rather than proven scientific facts (Wilson 1998a, 248−54).

Wilson's approach to the pursuit of unity of knowledge is illustrated by his understanding of the place of philosophy within this spectrum of possibilities. “Philosophy, the contemplation of the unknown, is a shrinking domain. We have the common goal of turning as much philosophy as possible into science” (Wilson 1998a, 11). Wilson anticipated being criticized for his “ontological reductionism” and “scientism,” but treated this as a badge of honor (Wilson 1998a, 11). These reductionist and scientistic tendencies are especially evident in his account of the origins and nature of religion (López 2011), in which the perceived explanatory power of evolutionary theory plays a decisive role. Wilson cites in his support Alexander Rosenberg, who he generously lauds as one of philosophy's “most distinguished practitioners.” Rosenberg would today be seen as representing a philosophically controversial strong form of scientism, which reduces reality to what physics is able to disclose (Rosenberg 2011; cf. Pigliucci 2016; Ridder, Peels and van Woudenberg 2018).

Although Wilson occasionally presents his project as a dialogue between the sciences and humanities, it has to be said that both the dominant intellectual substance and the rhetorical tone of Consilience is that of the natural sciences conquering the humanities (Bernstein 1998; Burnett 1998; McCarthy 1999, 842−63). Where some aim to encourage dialogue between the sciences and humanities, a close analysis of the rhetoric of Consilience suggests that it seems to have been intended to “fuel interdisciplinary hostilities” (Ceccarelli 2001, 128−56). It is, for example, difficult to instance points at which Wilson explicitly allows that the humanities might help achieve a better understanding or implementation of the natural sciences. Although many will be sympathetic to Wilson's appeal for the synthesis of the various elements of human knowledge in the quest for wisdom, there seems to be no two‐way traffic envisaged in the pursuit of human wisdom; the only hope of progress in achieving wisdom appears to lie in increasing the influence of the natural sciences. Wilson's critics thus point, for example, to his explicitly stated desire to capture “the moral realm and render it under scientific and material control” (Segerstrale 2006, 47; cf. Klinefelter 2000).

Though presenting his approach as a responsible quest for a foundation of the unity of human knowledge, Wilson ultimately lays a theoretical framework for the scientific domination of the humanities through the use of scientific “bridging disciplines.” “Confidence in the unity of knowledge—universal consilience—rests ultimately on the hypothesis that all mental activity is material in nature and occurs in a manner consistent with the causal explanations of the natural sciences” (Wilson 1998b, 18).

Wilson's assertion of the intellectual hegemony of the natural sciences, particularly evolutionary science, is grounded in the capacity of the sciences to position and reductively explain other disciplines through what might now be described as a “metaphysics of power and influence” (Corry 2019, 216). In his important study of the rationale of theory choice in considering rival moral traditions, the philosopher Alasdair MacIntyre makes the point that a worldview or narrative that seeks to achieve intellectual or cultural hegemony over its rivals needs to show that it is “able to include its rivals within it, not only to retell their stories as episodes within its story, but to tell the story of the telling of their stories as such episodes” (MacIntyre 1990, 81). MacIntyre's reflections cast light on Wilson's strategy at this point. For Wilson, it is important to be able to show that the social sciences, the humanities, and religion can all be located, accommodated, and evaluated within the greater explanatory capacity of the natural sciences. To claim to be able to explain something scientifically is thus an implicit assertion of the intellectual hegemony of the natural sciences.

Wilson's understanding and implementation of the concept of consilience suggests that it has little value for those concerned with fostering a two‐way intellectual dialogue between, and mutual understanding of, science and the humanities. Recognizing this point, some scholars have more recently sought an approach to consilience that avoids such an explicit privileging of the natural sciences. Slingerland and Collard, for example, argue that Wilson's approach creates the impression that “consilience involves the sciences engulfing the humanities—a prospect that is understandably off‐putting for humanists … it is better to think of consilience as an attempt to develop a new, shared framework for the sciences and humanities” (Slingerland and Collard 2011, 4), including the relation of science and religion. Yet it has to be said that even those who have subsequently expressed a preference for this more sophisticated “second wave” of consilience still offer in practice what many would consider to be a reductionist account of the origins of religion (e.g., Norenzayan and Gervais 2011), apparently on the basis of the questionable assumption that to offer reasons for the historical origins of religion amounts to an explanation of its contemporary utility or appeal.

Yet our concern in this article focusses on the significant challenge to Wilson's interpretation of the notion of “consilience” offered in 2003 by Gould. In what follows, I shall set out Gould's concerns about Wilson's approach to consilience, and explore how Gould's own approach to this topic—which he considers to represent a retrieval and reappropriation of Whewell's original idea—can be used to develop a viable working relationship between the natural sciences and the humanities in general, and religion in particular.

Gould's Critique of Wilson

Gould's critique of Wilson's understanding and application of the notion of consilience has two main components. First, Gould demonstrates that Wilson misrepresents William Whewell's concept of consilience, in effect repurposing it for his agenda of establishing scientific dominion over the humanities; second, he sets out significant critiques of some of its individual elements (Gould 2003, 205−15). Gould's analysis leads him to conclude that Wilson has adapted Whewell's ideas for his own purposes, suppressing those elements he finds inconvenient, and extending those he finds congenial to the point at which they become inconsistent with Whewell's position. Gould's close reading of Wilson's Consilience indicates that Wilson has little interest in engaging Whewell, fails to appreciate Whewell's significance as a philosopher of science in enabling Darwin to move from a mass of observations to a coherent theory, and appropriates Whewell's term for his own ends.

For Gould, Whewell was concerned to understand “the process of induction, or movement from repeated observations to general conclusion” (Gould 2003, 207). He developed the concept of consilience in order to account for a “‘jumping together’ of disparate facts into a common structure of explanation” (Gould 2003, 209). Gould suggests that Darwin's Origin of Species represents “the most brilliant example ever constructed for the power and efficacy of consilience as a method of proof in natural history” (Gould 2003, 211). It enabled Darwin to make “coordinated sense” of a set of seemingly disparate observations.

Yet Whewell did not treat consilience as a method of reduction. Indeed, Whewell's own analysis points to consilience being seen as additive. The phenomena are not denied or diminished; something is added to them in order to explain them. “There is a New Element added to the combination [of instances] by the very act of thought by which they were combined” (Whewell 1847, vol. 2, 48). Whewell held that this “act of thought” was to be understood as a mental operation of bringing together a number of empirical facts by “superinducing” upon them a way of thinking that unites the facts. For Whewell, this renders them capable of being expressed by a general law, which both identifies and illuminates the “true bond of Unity by which the phenomena are held together” (Whewell 1847, vol. 2, 46). A similar point is made later in the nineteenth century by the American philosopher Charles S. Peirce, in a discussion of the nature of theoretical explanation that parallels Whewell's reflections on deficiencies in Aristotle's account of induction (Flórez 2014). For Peirce, a good theory “adds something to [observations] … because the addition serves to render intelligible what without it, is unintelligible” 2008, 466).

Gould clearly sees that Whewell's concern is not to diminish nature, but to enable a more effective human comprehension of its interconnections. Gould's critique of reductionist accounts of scientific explanation, such as that he finds in Wilson's Consilience (York and Clark 2005, 292−93), is partly grounded in his realization that explanation adds something to observations to render them intelligible and coherence. Perhaps more significantly, Gould rightly discerned that Whewell does not consider that the explanatory styles and strategies deployed in the natural sciences can be extended into the humanities (Gould 2003, 215). Whewell, Gould argues, does not understand consilience in terms of “a single consilient chain” that can be applied to all disciplines, leading to the “unification of all knowledge along a single chain of rising complexity,” arguing instead for “irreducible different ways of knowing” (Gould 2003, 254). Where Whewell “regarded the humanities (particularly moral and religious reasoning) as a set of logically and inherently separate ways of knowing,” Gould points out that Wilson wants to subsume them within the “single reductionist chain” offered by the natural sciences (Gould 2003, 255).

Gould thus recognizes a multiplicity of valid research methods, adapted to their specific objects of interpretation and disciplinary fields of study, and rejects Wilson's notion of evolutionary theory as a single research method that can be used universally. Wilson, in developing his point, insists that evolutionary theory is not merely a resource from which the humanities can benefit; it is a controlling paradigm by which they are to be understood. This is particularly clear in his remarkable preface to a collection of essays on what we might call “Darwinian Lit‐Crit” (Wilson 2005; cf. Pinker 2007), which appeared too late to be considered by Gould, but nevertheless exhibits precisely the concerns he identified. Wilson here speaks of the “sciences and the humanities united,” while setting this bold affirmation in a context that clearly privileges the sciences.

Gould points out that Wilson appears to believe that speculative accounts of the origins of human moral values or artistic tastes confirms their present utility and validity:

Wilson makes a doubly false transition: first, from this speculative theory about origins to a claim about current and continuing utility of the arts; second, and more serious, from a claim that the magisterium of science about the emotional utility of art to a definition of truth and beauty in the magisterium of ethics (Gould 2003, 241).

Although Gould makes this point with reference to aesthetic issues, it is part of his broader critique of Wilson, perhaps seen at its most effective in his faulting of Wilson's speculative argument for an objective scientific basis for ethics (Gould 2003, 241−46).

Gould notes that while a case can be made for the evolutionary origin of ethics, this issue is located on “an irrelevant periphery of the great moral debates in the history of scholarship and human life.” For Gould, science can help us with such “nonempirical questions about the meaning of existence and the definition of goodness,” without dislodging their primary location “within the logics and methods of the magisterium of the humanities” (Gould 2003, 246). Gould argues that Wilson, in pursuing his “reductive consilience,” ends up believing not merely that biological accounts may be offered for the origins of human ethics or the artistic sensibilities of humanity, but that these may tell us what these moral and aesthetic values ought to be.

Conclusion

Gould is often presented as a representative of an approach to science and religion that emphasizes their independence, and hence their disconnectedness, thus isolating them from meaningful interaction or dialogue. This article has sought to bring out the intellectual depth of Gould's (2003) position on this matter as a matter of importance in itself, highlighting the importance of his engagement with intellectual history, while pointing to his potential contribution to the kind of interdisciplinary dialogue that lies at the heart of the field of science and religion. Gould's bold statement of the relation of science and the humanities sets his views on science and religion in their proper context:

I too seek a consilience, a “jumping together” of science and the humanities into far greater and more fruitful contact and coherence—but a consilience of equal regard that respects the inherent differences, acknowledges the comparable but distinct worthiness, understands the absolute necessity of both domains to any life deemed intellectually and spiritually “full,” and seeks to emphasize and nurture the numerous regions of actual overlap and common concern (Gould 2003, 259).

It seems that Gould's anxiety at Wilson's flawed account of consilience led him to expand his earlier understanding of the relation of science and religion, allowing both that there are “numerous regions of actual overlap,” and actively encouraging their exploration and nurture.

Far from placing some kind of embargo on intellectual traffic between these disciplines, Gould is concerned to maintain their integrity and autonomy in the face of Wilson's approach in Consilience. Gould recaptures something of the scope and breadth of Whewell's original vision, in which we are called on to “recognize the different light” that science and religion “each can shine upon a common quest for deeper understanding of our lives and surroundings in all their complexity and variety” (Gould 2003, 251). He offers us an (admittedly underdeveloped) intellectual framework for an informed and productive conversation between science and religion, two of the most prominent patches of Gould's “beautiful and integrated coat.” Perhaps we need to draw on others to help solidify and consolidate their interaction and the integration of their outcomes; yet Gould surely lays a foundation on which we may build further.