Charles Darwin’s Theory of Moral Sentiments:What Darwin’s Ethics Really Owes to Adam Smith
When we read the Origin, we cannot help but hear echoes of the Wealth of Nations. Darwin’s “economy of nature” features a “division of labour” that leads to complexity and productivity. We should not, however, analyze Darwin’s ethics through this lens. Darwin did not draw his economic ideas from Smith, nor did he base his ethics on an economic foundation. Darwin’s ethics rest on Smith’s notion from the Theory of Moral Sentiments of an innate human faculty of sympathy. Darwin gave this faculty an evolutionary interpretation and built on this foundation an ethics far removed from what is commonly supposed.
Charles Darwin, Adam Smith, William James, economy of nature, division of labor, social Darwinism, evolutionary ethics, ethics, evolution
In Wealth of Nations,1 Adam Smith argued that individuals in a market economy pursue their self-interest. The more talented and industrious thrive, and the less so scratch out a more precarious existence. Yet although individuals seek only their own advantage, the economy as a whole becomes more efficient and productive. In Origin of Species,2 Charles Darwin argued that organisms compete for scarce resources. The stronger and more resourceful thrive, and the less so weaken and die. As a result, nature increases in complexity and productivity. It is unsurprising that Darwin’s theory has often been read as an apologia for laissez-faire moral codes. Smith developed a laissez-faire theory of political economy. Darwin turned that economic theory into a biological fact, and so gave laissez-faire a scientific grounding. Counternarratives have also been offered. Some argue that Darwin’s demonstration of how nature is tells us nothing about how we ought to behave. Others point to Darwin’s interest in cooperation between organisms and see support for communitarian ethics. Despite their diversity, [End Page 571] these narratives share a common core: the central fact with which our ethics must deal is individual pursuit of self-interest in an atmosphere of competitive struggle. We may celebrate that fact, or we may decry it, but there it sits, stubbornly, at the center of our moral reasoning, demanding that we respond.
These narratives, however, get Darwin wrong. Although Darwin’s conception of nature’s economy is similar to Smith’s notions of political economy, Darwin did not draw his ideas from Smith. More fundamentally, Darwin’s ideas about the economy of nature are not central to his ethical thinking. Darwin did apply one of Smith’s ideas to questions of ethics, but that idea came from Theory of Moral Sentiments,3 not Wealth of Nations. Darwin based his ethics on a creative refashioning of Smith’s notion that human morality rests on the innate faculty of “sympathy.” And Darwin built on that foundation an ethics that had no connection whatever to laissez-faire morality.
I end my essay with a coda. Although my reading of Darwin’s ethics departs from the dominant trend, it is not without precedent. A century ago, William James propounded a similar interpretation of Darwin. James’s interpretation has been largely forgotten, but he had Darwin right. Indeed, James seems to have developed his own moral philosophy on what he saw as a Darwinian foundation. Although I can only gesture at the issue here, a reevaluation of how James adopted, and transformed, Darwin’s ethics is overdue.
DARWIN’S ETHICS AND WEALTH OF NATIONS
In Wealth of Nations, Smith imagined a tribe of hunters. One member makes good weapons but is an indifferent hunter. He finds that he does better by making weapons and trading them for game than he could by hunting. Other members of the tribe learn to focus on their strengths.4 Everyone seeks only their own interest and cares nothing for the general good. But their selfishness leads to a “division of labour,”5 resulting in increased production.6 Each is “led by an invisible hand to promote an end which was no part of his intention,”7 the maximization of the productive [End Page 572] capacity of the entire economy. This phenomenon reaches its apotheosis in industrial capitalism, as in the example of the pin factory, where Smith attributed an astounding increase in productivity to the division of labor.8 An economy therefore produces the most wealth when individuals compete to achieve their private interests; the invisible hand guarantees the best economic interests of the community as a whole.9
Compare Darwin’s theory of evolution. In nature’s “economy”—a term Darwin deployed eighteen times in the Origin—organisms compete to survive and reproduce. This “struggle for existence” is central to the evolutionary process. The Origin’s subtitle references “the Struggle for Life.” Chapter 3 is entitled “The Struggle for Existence.” In the first edition, Darwin employed “struggle” 67 times, “battle” nine times, and “war” four times. As in economic competition, in the struggle for existence, different organisms are better at exploiting different resources, giving rise to a natural “division of labour”—a locution Darwin used five times. This division of labor is “profitable,” as if guided by an invisible hand: “So in the general economy of any land, the more widely and perfectly the animals and plants are diversified for different habits of life, so will a greater number of individuals be capable of there supporting themselves.”10
The echoes of Smith are unmistakable. And, beginning shortly after the publication of the Origin, those echoes were widely considered to pose a problem in ethics: if nature is characterized by competitive struggle, and if struggle maximizes the overall good, does not Darwin’s theory mean that each individual should be encouraged to pursue their self-interest? The answers to this question have varied widely. But what has varied little is the deeply held assumption that this is the basic question—that the implications of Darwin’s theory for ethics are fundamentally bound up with competition and struggle.
Shortly after the Origin appeared, Karl Marx wrote a letter to Friedrich Engels commenting on the connection between Darwin’s ideas and economics: “It is remarkable how Darwin rediscovers, among the beasts and plants, the society of England with its division of labour, competition, opening up of new markets, ‘inventions’ and Malthusian ‘struggle for [End Page 573] existence.’”11 Engels later extended Marx’s argument. Darwin’s theory was a trick intended to naturalize customary economic arrangements: “The whole Darwinian theory of the struggle for existence is simply the transference from society to animate nature of Hobbes’ theory of the war of every man against every man and of the bourgeois economic theory of competition together with the Malthusian theory of population. This feat having been accomplished … the same theories are next transferred back again from organic nature to history and their validity as eternal laws of human society declared to have been proved. The childishness of this procedure is obvious.”12 The narrative is clear: a social theory purported to justify laissez-faire capitalism; Darwin refashioned that theory into a law of nature, providing laissez-faire ethics with a scientific foundation.
Not all of Darwin’s contemporaries agreed. Thomas Henry Huxley argued that, although Darwin had proved that nature works through struggle, he had said nothing about how we ought to respond morally to that fact: “There is another fallacy which appears to me to pervade the so-called ‘ethics of evolution.’ It is the notion that because, on the whole, animals and plants have advanced in perfection of organization by means of the struggle for existence and the consequent ‘survival of the fittest’; therefore men in society, men as ethical beings, must look to the same process to help them towards perfection.”13 Although Huxley thus rejected Marx’s and Engels’s reading of Darwin, he shared their assumption that competitive struggle in nature is central to the ethical implications of Darwinism.
Around the turn of the twentieth century, a growing number of naturalists began to challenge the notion that competition is the primary driver of evolution.14 Evolution, it was suggested, favored organisms that behave cooperatively, even altruistically, over those that compete. For Jean-Louis de Lanessan, individuals succeed by joining into cooperative groups.15 Peter Kropotkin contended that “the fittest” are “those animals which acquire habits of mutual aid.”16 These ideas entered too into discussions of the [End Page 574] implications of Darwin’s theory for ethics. Henry Drummond argued that the “ascent of man” was due far less to competitive struggle than to a “Struggle for the Life of Others,” or “Altruism.” Altruism “assumes a sovereignty before which the earlier [competitive] Struggle sinks into insignificance.”17 These ideas differed substantially from those of Marx, Engels, and Huxley; yet they still placed competition and struggle at the center of their analysis of Darwinism’s implications for ethics.
With the coming of the neo-Darwinian orthodoxy of the modern synthesis, the ideas of de Lanessan, Kropotkin, and Drummond for the most part faded away. More recent discussions about the ethical implications of Darwinism have tended to reprise the debate between Marx/Engels and Huxley. Silvan Schweber took over the Marx/Engels role: “[W]hen he adopted … Adam Smith’s insight into the competitive advantage of the division of labour, Darwin was aware that he was ‘biologizing’ the explanations political economy gave for the wealth of nations.”18 Stephen Jay Gould agreed that Darwin’s theory “is, in essence, Adam Smith’s economics transferred to nature.”19 But describing how nature works does not offer moral instruction. On that question, Gould, like Huxley, saw Darwin as agnostic: “Darwin argues [that] we must simply admit that nature offers no moral instruction at all.”20 On this reading, Darwinism does not justify laissez-faire ethics. But competition and self-interest are still the central problem. Precisely because nature is built on competitive struggle, we must base our ethics on something outside of nature. Huxley argued that “the ethical progress of society depends, not on imitating the cosmic process, … but in combating it.”21 And Gould advised us to find our moral guidance in the “magisterium” of religion, rather than that of science.22
The tendency to treat competitive struggle as central to the ethical implications of Darwinism is not universal,23 but it dominates the discourse [End Page 575] and leads to confusion about Darwin’s ethical thinking. Darwin had a well-defined theory of ethics. It did not celebrate competitive struggle, nor did it praise altruistic cooperation. Neither did it advise us to seek outside of nature for moral guidance. Ironically, Darwin’s ethics do owe much to his reading of Smith. It was not, however, from Wealth of Nations that Darwin drew his inspiration, but from Moral Sentiments. Darwin refashioned Smith’s concept of a moral sentiment of sympathy into an ethical theory profoundly different from what is commonly supposed. Before turning to this topic, however, I will first explore the claim that Darwin derived his ideas about the “economy of nature” from Wealth of Nations.
THE ECONOMY OF NATURE AND THE DIVISION OF LABOR
It is easy to suppose that Darwin must have gotten the idea to figure nature as an “economy” from Smith, or at least from someone we would recognize as an “economist.” Isn’t it true that the word “economy” means the relations among the productive resources of a human community? And isn’t the “economy of nature” merely a metaphor that asks us to consider nature as akin to an actual economy? In short, no.
Although we tend to think of “economy” as relating to wealth, it has long been applied much more widely.24 In the seventeenth century, Hobbes used the “œconomy of a Common-wealth” to refer not to its material resources, but to its general structure and organization.25 Others applied “economy” to other bodies, even immaterial ones, as with the “economy” of the Holy Trinity.26 This period also witnessed the first recorded appearances of the “economy of nature.” Kenelm Digby ascribed the falling of dense bodies to the “economy of nature,” as did Samuel Collins with the circulation of blood.27 [End Page 576]
The first extended disquisition on the “economy of nature” was a 1749 lecture by Carolus Linnaeus: “By the Œconomy of Nature we understand the all-wise disposition of the Creator in relation to natural things, by which they are fitted to produce general ends.”28 In 1791, Darwin’s grandfather, Erasmus, rendered the Linnaean system in verse, titling one poem “The Economy of Vegetation” and using the idea of a natural “economy” throughout.29 Alexander von Humboldt used the term repeatedly in his Personal Narrative, published between 1814 and 1829.30 And Charles Lyell deployed “economy of nature” or some variant 30 times in the first edition of The Principles of Geology, including in the epigraph.31
Thus “economy” originally meant how a given domain was structured or organized. The application of “economy” to the relations of production has no more pedigree than its application to the relations among organisms, the parts of the Holy Trinity, or the organizations making up a political commonwealth. Indeed, if the financial sense of economy was born around the publication of Wealth of Nations in 1776, that meaning of economy post-dates the discussions of the “economy of nature” by Digby, Collins, and Linnaeus.
It is probable that Darwin derived his notion of the economy of nature more from earlier naturalists than from Smith. By the time the Beagle sailed, Darwin had carefully read his grandfather’s works.32 And they were important to him: he began his first transmutation notebook with the title Zoonomia,33 the title of one of Erasmus Darwin’s treatises.34 Darwin’s debts to Humboldt were even deeper: Darwin wrote that Humboldt’s work “far exceed[s] in merit” everything else he had read on the Americas, and wrote of Humboldt that “he like another Sun illumines everything I [End Page 577] behold.”35 Darwin’s debts to Lyell were no less extensive. Darwin put Lyell at the head of his list of “our greatest geologists,” credited Lyell with producing “a revolution in natural science,” and expressed confidence in some of his own ideas because “they are in strict accordance with the general principles inculcated” by Lyell.36
Charles Darwin first used the term “economy of nature” in 1833.37 He used it again in 1835,38 twice again in notes compiled between 1832 and 1837,39 and in his transmutation notebooks in 1838.40 Darwin read Linnaeus’s discussion of the economy of nature in 1841.41 He used the term eighteen times in a private sketch he made of his theory in 1842, and it remained equally prominent in his 1844 expanded sketch and in the published version of the Origin.42
As for the notion that Darwin might nonetheless have derived the term from Smith, it is impossible to prove a negative, but the idea is far-fetched. Darwin kept meticulous records of his reading but never mentioned having read Wealth of Nations. This is not to claim that Darwin was unfamiliar with Smith’s ideas on political economy. Darwin read at least parts of Dugald Stewart’s treatise on Smith.43 However, the earliest evidence of Darwin’s familiarity with Smith’s economic theories dates from 1840, years after Darwin’s first discussions of the “economy of nature.” Moreover, to whatever extent Darwin drew on Smith’s ideas in delineating the features of the economy of nature, Smith may well have derived his own idea of the economy of nature from the same naturalists whom Darwin had been reading. As Margaret Schabas has shown, Smith’s library contained many [End Page 578] volumes of natural history, including a copy of Linnaeus’s Œconomy of Nature, and Smith’s treatment of the subject distinctly echoes Linnaeus. Schabas concludes: Smith’s “construal of these [economic] phenomena reflects their links to nature.… [I]n his treatment of … labor …, Smith drew on recent developments in the natural sciences.”44
In short, the notion that Darwin took ideas developed by Smith in the context of political economy and applied them to the natural world is unpersuasive. The evidence strongly suggests that Darwin derived the idea of the economy of nature from Linnaeus, his grandfather, Humboldt, Lyell, and the other naturalists with whom he was in constant intellectual dialogue. Smith may possibly have been another conduit for similar ideas, but was unlikely to have been more than that.
Even if Darwin did not get the idea of the “economy of nature” from Smith, one might argue that what really matters is not whether nature is an economy, but how economies work. The idea Darwin borrowed from Smith, the argument would proceed, is that, like a human economy, nature is characterized by competition for resources, which gives rise to a division of labor, which ensures that the natural economy will support the largest possible output. Thus was laissez-faire capitalism biologized.
On balance, it appears that Darwin drew his conception of the “division of labour” predominantly from naturalists, although here the matter is a bit more uncertain. Darwin never mentioned Smith in discussing the division of labor. Rather, he attributed the notion to the naturalist Henri Milne-Edwards,45 who had shown that complex organisms are differentiated, such that “the life of the individual results from the ensemble of heterogeneous elements, all more or less dependent on one another.”46
Around the same period, naturalists were investigating specialization of a different sort—how different organisms living together in a particular geographical area specialize in using different resources from that area. In 1820, Augustin de Candolle suggested that different plants in a particular area prefer different soil types, and therefore inhabit different “stations.”47 Lyell [End Page 579] carried the idea further by highlighting that a station is as much defined by the other creatures living in the vicinity as by climate, soil, and the like.48
Darwin put these two ideas together, arguing that the specialization of different organisms within a single geographic area was a kind of division of labor that would result in the area as a whole being more productive in the amount of life it could support:
The advantage of diversification in the inhabitants of the same region is, in fact, the same as that of the physiological division of labour in the organs of the same individual body—a subject so well elucidated by Milne Edwards. No physiologist doubts that a stomach by being adapted to digest vegetable matter alone, or flesh alone, draws most nutriment from these substances. So in the general economy of any land, the more widely and perfectly the animals and plants are diversified for different habits of life, so will a greater number of individuals be capable of there supporting themselves.49
As with the “economy of nature,” the similarities between Smith’s division of labor in a factory and Darwin’s among living organisms is palpable. But similarity does not necessarily entail filiation. We have seen how tenuous the links are between Darwin and Wealth of Nations. In contrast, in a letter sent before the publication of the Origin, Darwin mentioned that he had been puzzling over de Candolle’s discussion of social plants due to its importance in “understand[ing] as much as I can of what has been called the economy of nature.”50 And we have seen the great attention and respect Darwin paid to his mentor and friend Lyell. Under the circumstances, it is likely that Darwin developed his ideas about the division of labor more under the influence of de Candolle and Lyell than under that of Smith.
I do not mean to suggest that Darwin was oblivious to the resonances between his theory and those of British political economists. Darwin had read several contemporary works on political economy and was a reader of journals that often discussed such issues.51 We have seen that he read [End Page 580] Stewart on Smith. And Darwin freely acknowledged his debts to the political economist Thomas Malthus,52 once reporting that it was only on reading Malthus that he “at last got a theory by which to work.”53 There are, moreover, some indications of a meaningful connection between Darwin’s specific ideas about the division of labor among organisms and similar ideas from political economists. Milne-Edwards, who first applied the term “division of labour” to organisms and whom Darwin cited as his source for the idea, himself attributed the idea to “modern economists.”54 Darwin may well have noted the similarities between his ideas of the economy of nature and the ecological division of labor to similar ideas of political economists. But Darwin had attributed the idea to Milne-Edwards. Darwin might, as Schweber argues,55 have been dissembling, but we have no reason so to assume. Darwin drew many of his ideas from sources other than naturalists and, as in the case of his debt to Malthus, never seemed to see that fact as a source of embarrassment. On balance, it seems appropriate to take Darwin at his word in this instance.
But where Darwin got the ideas of the economy of nature and the division of labor is not the critical point. More fundamental for my purposes is whether—wherever Darwin got those ideas—he considered them to be relevant to ethics. On this question, the answer is an absolutely clear no. Even if Darwin did get those ideas from Smith—or more likely, recognized the resonances of his notions with those of political economists—that is irrelevant to Darwin’s ethical views. Darwin had a clear ethical theory, and it had nothing to do with Wealth of Nations or laissez-faire capitalism. I will now turn to an examination of that theory.
CHARLES DARWIN’S THEORY OF MORAL SENTIMENTS
For the reader who has only viewed Smith through the lens of Wealth of Nations, Moral Sentiments comes as something of a surprise.56 There, [End Page 581] Smith argued that each human has instinctual “principles in his nature which interest him in the fortune of others, and render their happiness necessary to him, though he derives nothing from it except the pleasure of seeing it.”57 We cannot experience others’ joys and sorrows directly, but only in imagination: “As we have no immediate experience of what other men feel, we can form no idea of the manner in which they are affected, but by conceiving what we ourselves should feel in the like situation.”58 Smith designated this “fellow-feeling with any passion whatever” as “sympathy”59 and considered it the foundation of our moral judgments. When we judge the morality of someone’s actions, we imagine ourselves facing the same situation and reflect upon how we would act in their place. If we imagine that we would act in the same way, we approve the actions “as proportioned and suitable to their objects”; if otherwise, we “disapprove of them, as extravagant and out of proportion.”60
For Smith, then, when we judge another’s behavior as right or wrong, we begin not by comparing that behavior to some absolute, external standard, but by examining the sympathetic response that we actually feel when we consider the behavior. This does not mean that each person’s moral code derives from their idiosyncratic emotional reactions to particular situations. Since sympathy is an innate feature of human nature—Smith even referred to sympathy as an “instinct”61—different people’s sympathetic responses to a particular case are likely to be to some significant extent consonant. Moreover, when we consider the morality of our own actions, Smith suggested that we engage in an imaginative reversal. We judge the morality of others’ acts by imagining how we would act in their place. Similarly, when we consider how to act ourselves, we place ourselves in the position of someone sitting in judgment of our actions and seek to adjust our actions so that they would meet the approbation of such a judge: “In order to produce this concord, as nature teaches the spectator to assume the circumstances of the person principally concerned, so she teaches this last in some measure to assume those of the spectators. As they are continually placing themselves in his situation, and thence conceiving emotions similar to what he feels; so he is as constantly placing himself in theirs, and thence conceiving some degree of that coolness about his own fortune, with [End Page 582] which he is sensible that they will view it.”62 Smith personified this “coolness” as the “impartial spectator.” In all our ethical judgments, but most especially when we evaluate our own behavior, we try to take not our own particular perspective, suffused with our interests and passions, but the perspective of a hypothetical person not engaged in the situation. We then consult, in imagination, this impartial spectator to see how they would evaluate the situation and make our moral judgments accordingly.63 Because we attempt to take the perspective of the impartial spectator, our moral judgments are not wholly subjective, but attain a level of congruence with those of our fellows.64
Whatever degree of congruence we might thus find, Smith never wavered in his rejection of the search for an external, absolute standard to which recourse could be had to determine whether an action is moral. Rather, Smith defended a naturalistic theory: “We are not at present examining upon what principles a perfect being would approve of the punishment of bad actions: but upon what principles so weak and imperfect a creature as man actually and in fact approves of it.”65 And those principles, thought Smith, were founded in the instinct of sympathy rather than in the application of our reason: “Mankind are endowed with … a desire of the continuance and perpetuity of the species.… But though we are in this manner endowed with a very strong desire of those ends, it has not been intrusted to the slow and uncertain determinations of our reason, to find out the proper means of bringing them about. Nature has directed us to the greater part of these by original and immediate instincts.”66 Smith therefore denied the possibility of any standard of morality founded in reason rather than instinct. Consider, for example, his treatment of utility. A particular action may conduce to utility, but its utility is not the original, or primary, reason that we judge it to be moral: “But still I affirm, that it is not the view of this utility or hurtfulness which is either the first or principal source [End Page 583] of our approbation and disapprobation. These sentiments are, no doubt, enhanced and enlivened by the perception of the beauty or deformity which results from this utility or hurtfulness. But still, I say, they are originally and essentially different from this perception.”67 For Smith, our moral judgments are founded in our instinct of sympathy. We interrogate and evaluate those judgments by asking ourselves whether an impartial spectator would share them, and to a lesser extent by a consideration of their consequences. But the innate human faculty of sympathy is foundational.
While he first began to explore his evolutionary ideas, Darwin read Moral Sentiments and was much struck by it, mentioning it several times in his notebooks.68 As we have seen, he also read Stewart’s Life of Smith, which included an extensive discussion of Moral Sentiments. Darwin also read a summary of Smith’s account of sympathy in James Mackintosh’s treatise on ethics.69 Darwin clearly understood Smith’s basic conception. He wrote in a notebook that Smith “derives all from sympathy.”70 He spelled the theory out in more detail in another entry: “Adam Smith says sympathy we can only know what others think by putting ourselves in their situation, & then we feel like them—hence sympathy.”71
Darwin initially had reservations about Smith’s theory. He wrote that “children disprove” Smith’s theory72 and that sympathy is “very unsatisfactory” as a source of moral feelings “because does not like Burke explain pleasure.”73 But Darwin was nonetheless struck by Smith’s naturalism, and in particular, Smith’s suggestion that human morality and animal instincts were intimately connected. Darwin wrote that Moral Sentiments “ought to be studied for comparison of man & animals” and echoed Smith’s idea that sympathy might be the origin of human moral “instincts.”74 This notion [End Page 584] that humans are animals resonated powerfully with Darwin: “Man in his arrogance thinks himself a great work worthy the imposition of a deity. [M]ore humble & I believe truer to consider him created from animals.”75 Not only have our bodies evolved, but also our minds, which he equated to animal instincts: “[T]he mind of man is no more perfect than instincts of animals to all & changing contingencies, or bodies of either.—”76 And he argued that human morality has its source in animal instinct and performs the same function in humans as instinct does in animals. As for source, Darwin wrote of the “social instincts, which as I hope to show is probably the foundation of all that is most beautiful in the moral sentiments of the animated beings.”77 Regarding function, he argued: “Society could not go on except for the moral sense, any more than a hive of Bees without their instincts.—… The change of our moral sense, is strictly analogous to change of instinct amongst animals.—”78
One passage in Darwin’s notebooks offers a vivid snapshot of Darwin’s debt to Smith, and of how he refashioned Smith’s ideas to give them an evolutionary cast. Smith had argued that we approve of actions primarily because of sympathy, and that any utility that flows from those actions is less the source of their moral goodness than a consequence of that goodness. Darwin made the same point, contrasting “[t]wo classes of moralists.” Utilitarians hold that “our rule of life is what will produce the greatest happiness.” The other class, in which we recognize Smith, “says we have a moral sense,” an innate faculty that guides our actions without regard to their utility. Darwin believed he had dissolved the controversy: an action is not moral because it will increase happiness in the future; rather, our moral sense has evolved out of what increased happiness in the past, which, because of its past value to human survival, has been fixed in us as a moral sense: “But my view unites both & shows them to be almost identical what has produced the greatest good or rather what was necessary for good at all is the instinctive moral sense.”79 Or, as he put it elsewhere: “I am tempted to say that those actions which have been found necessary for long generation, (as friendship to fellow animals in social animals) are those which are good & consequently give pleasure, & not … those that on long run will do good.—alter will in all cases to have & origin as well as rule [End Page 585] will be given.—”80 Note the echoes of Moral Sentiments: Smith had found a source of morality in our “desire of the continuance and perpetuity of the species.”81 But note too Darwin’s reinterpretation of Smith’s ideas through an evolutionary lens—for Smith, due to unchanging human nature, we desire to perpetuate the species. For Darwin, the social instincts have in the past favored the perpetuation of the species, and so have become fixed in the human lineage.
Darwin would not publish his views on the evolution of morality for another thirty years. When he did so, however, he had resolved his reservations about the centrality of sympathy. He cited Smith, especially “the first and striking chapter” of Moral Sentiments, and identified “the all-important emotion of sympathy” as the source from which the social instincts evolved.82 Otherwise, the argument proceeded as it had in the notebooks. Humans are animals: “[W]e ought frankly to admit [the] community of descent” of “man and all the other vertebrate animals.”83 Human mental capacities are as much evolved attributes as the wings of the bat or the migratory instincts of the swallow: “We have now seen that man is variable in body and mind; and that the variations are induced, either directly or indirectly, by the same general causes, and obey the same general laws, as with the lower animals.”84
And he continued to interpret sympathy in evolutionary terms. For Smith, sympathy was an innate and unchanging instinct derived from seeing the pains and pleasures of others. For Darwin, sympathy may have originated in this way, but it then evolved. Darwin began with an account of sympathy that could have come directly from Smith: “[O]ur regard for the approbation and disapprobation of our fellows depends on sympathy, which as we shall see, forms an essential part of the social instinct, and is indeed its foundation-stone.”85 And Darwin placed great emphasis on “sympathy,” using the term 57 times in the Descent. Yet if evolution’s reach extends to human instinctual behaviors and mental capacities, Darwin reasoned, it extends too to human morality, for morality is the outgrowth of those instincts and capacities: “The following proposition seems to me in a high degree probable—namely, that any animal whatever, endowed with well-marked social instincts, would inevitably acquire a moral sense or conscience, as soon as its intellectual powers had become as well developed, or [End Page 586] nearly as well developed, as in man.”86 Thus, in the human lineage, sympathy evolved into the social instincts, which Darwin considered to be especially strong among members of the same community of organisms.87
Darwin also echoed Smith’s argument that sympathy entails not merely imagining ourselves in another’s position when we judge their actions, but also imagining how others would judge our actions: “If any desire or instinct, leading to an action opposed to the good of others, still appears to a man, when recalled to mind, as strong as, or stronger than, his social instinct, … he will be conscious that if his conduct were known to his fellows, it would meet with their disapprobation; and few are so destitute of sympathy as not to feel discomfort when this is realised.”88
Darwin continued to reject utility as the foundation of moral judgment, again basing his argument on an evolutionary refashioning of Smith’s idea of sympathy. Darwin read John Stuart Mill to believe that moral feelings are not innate, but acquired during our lives. Darwin countered: “[I]t can hardly be disputed that the social feelings are instinctive or innate in the lower animals; and why should they not be in man?”89 To those who would claim that moral feelings are acquired during an individual’s lifetime, Darwin riposted: “On the general theory of evolution this is at least extremely improbable.” The idea will “be hereafter judged as a most serious blemish on the works of Mr. Mill.”90
In sum, Darwin’s ethics is founded on an evolutionary refashioning of Smith’s innate human faculty of sympathy. Darwin believed that social animals are born with the instinct of sympathy. As social animals develop intelligence equivalent to the human, that faculty evolves into the social instincts, and those instincts then determine what is and is not moral in the particular lineage. On Darwin’s theory, morality is, and is only, the set of norms and behaviors that, in any given lineage, have so evolved. This is a radically evolutionary ethics. Just as Smith’s in Moral Sentiments, Darwin’s ethics are naturalistic: human moral questions cannot be adjudicated by reference to any absolute, external source, but are founded in our innate faculty of sympathy and processed through our faculty of reflective reason. But Darwin refashioned Smith’s naturalism into an evolutionary ethics: what that innate faculty holds to be moral for any particular lineage of organisms is whatever that lineage has evolved to consider moral. [End Page 587]
Darwin’s approach to ethics thus has nothing whatever to do with laissez-faire, the division of labor, or the invisible hand. He ridiculed the notion that he was providing cover for laissez-faire ethics: “I have received in a Manchester Newspaper a rather a good squib, showing that I have proved ‘might is right,’ & therefore that Napoleon is right & every cheating Tradesman is also right—.”91 Neither did he defend an ethics based on cooperation for the common good, as suggested by de Lanessan, Kropotkin, and Drummond. Darwin rejected not only laissez-faire, but also any particular ethical code that purports to be independent of time, place, and conditions of life.
Nor should we confuse Darwin’s position with the argument put forth by such as Huxley and Gould that evolution has nothing to tell us about morality. For Darwin, evolution is the source of morality. In contrast to Huxley and Gould, Darwin believed that there is no absolute source of right and wrong outside of evolutionary history. For any particular lineage of intelligent social animals, there are clear and well-defined standards of morality. But those standards are and are only the ethical norms that have evolved in that lineage under its particular conditions of life. Darwin believed that his theory proved that no ethical norm has any claim to absolute validity, a principle equally at odds with laissez-faire individualism, communitarianism, and the notion that science can tell us nothing about the moral realm.
It might be questioned whether Darwin really held true to these ideas. Am I not attributing to Darwin an ethical relativism at odds with his strong moral convictions? Darwin believed, for example, that slavery is a “great sin.”92 He considered that he had convincing arguments for this belief, leading to an explosive dispute with Captain Fitzroy over the morality of slavery. And he was willing to stand up for his beliefs—he very nearly quit the Beagle after the argument.93 But there is no inconsistency. Darwin’s belief that morals are evolved attributes no more required him to refuse to make moral judgments than his belief that legs are evolved attributes required him to refuse to walk. Darwin believed that people (himself included) have strong moral views precisely because they are social animals with mental capacities developed to the point that a moral sense has evolved. Nor did Darwin consider that people’s moral beliefs are somehow invalid or delusive. Darwin believed that moral codes cannot be justified by recourse to [End Page 588] any absolute or transcendental principle external to the particular lineage in which those moral codes have evolved. But within and for a community of organisms with a common evolutionary history, moral judgments can be and are made and can be and are considered valid.
What Darwin denied is that there is any source external to our particular evolutionary situation on which to ground our moral views. According to Darwin, evolution occurs not in a static environment, but under the “complex and sometimes varying conditions of life.”94 As we have seen, what applies to a physical structure applies equally to instincts, mental faculties, and, ultimately, the moral sense. For Darwin, a moral judgment can only be valid for a particular lineage, evolved under its particular conditions of life. Thus, while all social animals with sufficiently well-developed mental capacities are, on Darwin’s view, bound to develop a moral sense, they are not bound to develop the same moral sense, and no external source can adjudicate between the competing moral rules:
I do not wish to maintain that any strictly social animal, if its intellectual faculties were to become as active and as highly developed as in man, would acquire exactly the same moral sense as ours. In the same manner as various animals have some sense of beauty, though they admire widely different objects, so they might have a sense of right and wrong, though led by it to follow widely different lines of conduct. If, for instance, to take an extreme case, men were reared under precisely the same conditions as hive-bees, there can hardly be a doubt that our unmarried females would, like the worker-bees, think it a sacred duty to kill their brothers, and mothers would strive to kill their fertile daughters; and no one would think of interfering.95
And we would be, in some sense, right not to interfere, thought Darwin. He knew that as humans we would find it “difficult” to do so, but “we ought to admire the savage instinctive hatred of the queen-bee,” as “maternal love or maternal hatred … is all the same to the inexorable principle of natural selection.”96
Could Darwin really have meant that there is no absolute standard against which moral claims can be set to judge their validity? In a word, [End Page 589] yes. In 1874, Francis Ellingwood Abbot, a Unitarian minister, sent a letter to Darwin enclosing a copy of an essay he had written and requesting Darwin’s comments.97 In his essay, Abbot had argued that moral obligations are absolute and apply universally: “Ethics treat of rights and duties among all moral beings, as objective and universal facts.… These obligations are not accidental or fortuitous; they are not one thing here and another thing there.… The relation of mutual Moral Obligation among all moral beings is just as objective, just as universal, just as necessary as the relation between the double triangles of the square.”98 Darwin rejected Abbot’s view: “I cannot see how morality is ‘objective & universal.’” He began his analysis with “lower social animals,” which “may be said to be under an obligation not habitually to kill each other, & the mothers to protect their offspring, … as the species c’d not exist in society without it.” But “No one w’d call [this] a moral obligation, & most persons w’d call it instinctive.” But instincts differ in different lineages and so are not everywhere the same: “Would you consider this an ‘objective & universal fact’? I suppose certainly not, as instinct is subjective & the obligation w’d differ to a certain extent for different species.” For Darwin, the same analysis applies to morals:
Now as soon as a social animal became in some slight, incipient degree a moral creature,—that is—was capable of approving or disapproving of its own conduct,—does it follow that its obligation w’d at once become moral? Would not the obligation remain, to a large extent, of the same so-called instinctive nature as before?… Even if the obligation of a moral being must be of necessity moral, I cannot see why it sh’d be an objective & universal fact, any more than with the instinctive obligation or bond between the lower social animals.99
Here, then, is Darwin’s evolutionary ethics in sharp relief. Morals evolve, and they cannot be judged from anywhere outside the evolutionary trajectory giving rise to them. [End Page 590]
There are clear affinities between Smith’s ideas in Wealth of Nations and Darwin’s in the Origin. We should, however, forswear the too-easy conclusion that Darwin applied Smith’s political economy to nature, providing a scientific foundation for laissez-faire ethics. A close analysis of the “economy of nature” and the “division of labour” suggests that Darwin developed these ideas primarily in dialogue with earlier naturalists. Moreover, nowhere did Darwin suggest that either of these ideas had any implications for ethics. When Darwin did articulate a theory of ethics, he based it not on Smith’s supposed defense of laissez-faire, but on an evolutionary reformulation of Smith’s idea of human moral sentiments. And that theory is entirely incompatible with laissez-faire or communitarian moral codes, as well as with any idea that morals find their justification in some absolute source outside of evolutionary history.
CODA DID JAMES DO TO DARWIN AS DARWIN DID TO SMITH?
My interpretation of Darwin’s ethics is not without precedent. Over a century ago, William James offered the same interpretation that I do here. While editing their father’s letters for publication, Darwin’s sons sent James copies of the Darwin–Abbot correspondence discussed earlier and asked for James’s opinion.100 James read Darwin’s response to Abbot just as I have:
But the main difference between your father & Mr. Abbot seems to be this, or something like it: Abbot thinks there is a real, objective, universal rightness or wrongness, grounded in the nature of things, absolute therefore, whether any discover & obey it or not.… Now I take it that your father meant to protest against this ideal of a perfection equally binding on all types of creature, no matter what their physiological differences.… For him the virtue of the rabbit could not with any kind of sense be measured by the same “objective” standard as that of the lion. The phrase is meaningless; virtue can’t swing in vacuo,—it is relative to the facts [End Page 591] of life, & these facts are wholly different in the case of the two objects, why not then call each right “in his way” & why not deny the existence of any rightness at all out of relation to the particular “way” of its subject.101
In closing, I propose a hypothesis that merits closer attention than I can give it here. As we have seen, Smith took sympathy to be an unchanging feature of human nature. Darwin refashioned sympathy into an outcome of an evolutionary trajectory, taking it in directions Smith never intended. James may well have done something analogous to Darwin. James understood Darwin to have rejected any absolute standard of morality in favor of different moral standards applicable to different lineages evolved under different conditions of life. And James was sympathetic: “I may add that I think your father’s way on the whole more sound than Abbot’s, that is more fruitful.”102
James’s letter quoted above predates virtually all of his published writings on moral philosophy. And there are reasons to believe that James had Darwin in mind when composing those published writings. In the essay in which James most comprehensively set forth his ethical views, he repeated almost verbatim words he had used in his letter to William: “Neither moral relations nor the moral law can swing in vacuo.”103 He also recapitulated one of Darwin’s most striking arguments for the impossibility of moral absolutes. Darwin had written that, if humans had been raised in the conditions of hive bees, we would practice infanticide without a blink. James made a remarkably similar point: “Were we lobsters, or bees, it might be that our organization would have led to our using quite different modes from these of apprehending our experiences. It might be too (we can not dogmatically deny this) that such categories, unimaginable by us to-day, would have proved on the whole as serviceable for handling our experiences mentally as those which we actually use.”104
For Darwin, there is no judging in the abstract between the ethics of the hive bee and the ethics of the human, because hive bees and humans evolved under different conditions of life. However, there is a standard that [End Page 592] is in a very real sense absolute for all hive bees, and a different one that is in the same sense absolute for all humans. For James, the conditions within which individuals make moral choices are different even for different beings with the same evolutionary history. Thus what is ethical, for James, is relative not just to evolutionary history, but also to individual character and circumstance: “[N]othing can be good or right except so far as some consciousness feels it to be good, or thinks it to be right.… [T]he real superiority and authority which are postulated by the philosopher to reside in some of the opinions, and the really inferior character which he supposes must belong to others, cannot be explained by any abstract moral ‘nature of things’ existing antecedently to the concrete thinkers themselves with their ideals.”105 James, I suggest, started with Darwin’s idea that beings in different evolutionary situations have different moral codes and generalized that idea so that it applies to any significant difference in two beings’ situations. Darwin had read Smith’s notion of sympathy through an evolutionary lens, remaking it into something very different and yet something clearly in the same intellectual lineage. It may be that James, in his turn, read Darwin’s ethical thought through a pragmatic lens and so refashioned it into something yet again very different, and yet again clearly in the same intellectual lineage. [End Page 593]
I would like to thank Jessica Riskin, Robert Proctor, Paul Robinson, Keith Baker, Jon Hodge, Ari Dubnov, and the anonymous reviewers for this journal for their insightful comments and questions. I also received valuable feedback when I presented an earlier version of this paper at the 2014 conference of the History of Science Society.
1. Adam Smith, An Inquiry into the Nature and Causes of the Wealth of Nations, 5th ed. (London: Methuen & Co., 1904).
2. Charles Darwin, On the Origin of Species by Means of Natural Selection (London: John Murray, 1859).
3. Smith, The Theory of Moral Sentiments, 6th ed. (London: A. Millar, 1790).
4. Smith, Wealth of Nations, 1.2.3. Citations to Wealth of Nations are to book, chapter, and paragraph.
5. Ibid., 1.1.1.
6. Ibid., 1.1.4.
7. Ibid., 4.2.9.
8. Ibid., 1.1.3.
9. But see ibid., 5.1.178 (without denying efficiency gains of division of labor, noting that its effect on workers can be mind-numbing). See also Emma Rothschild, Economic Sentiments: Adam Smith, Condorcet, and the Enlightenment (Cambridge: Harvard University Press, 2001), 116–56 (emphasizing this aspect of Smith’s thought).
10. Darwin, Origin, 115–16.
11. Karl Marx, Letter to Friedrich Engels, 18 June 1862, in The Collected Works of Karl Marx and Friedrich Engels, vol. 41 (London: Lawrence & Wishart, 1975–2005), 380–82.
12. Friedrich Engels, Letter to Pyotr Lavrov, 12–17 November 1875, in Labour Monthly (July 1936): 437–42.
13. Thomas H. Huxley, “Evolution and Ethics,” in Evolution and Ethics and Other Essays (New York: D. Appleton and Company, 1902), 46–116, at 80.
14. See Peter J. Bowler, The Eclipse of Darwinism (Baltimore: Johns Hopkins University Press, 1983).
15. J.-L. de Lanessan, Étude sur la doctrine de Darwin: La lutte pour l’existence et l’association pour la lutte (Paris: O. Doin, 1881).
16. Peter Kropotkin, Mutual Aid: A Factor of Evolution (London: William Heinemann, 1910), 6.
17. Henry Drummond, The Ascent of Man (New York: James Pott & Co., 1894), 13.
18. Silvan S. Schweber, “Darwin and the Political Economists: Divergence of Character,” Journal of the History of Biology 13, no. 2 (1980): 195–289, at 212. See also 212–13.
19. Stephen Jay Gould, The Structure of Evolutionary Theory (Cambridge: Belknap Press of Harvard University Press, 2002), 122.
20. Gould, Rocks of Ages: Science and Religion in the Fullness of Life (New York: Ballantine Books, 2002), 196.
21. Huxley, “Evolution and Ethics,” 83.
22. Gould, Rocks of Ages, 5–6.
23. See, e.g., Thomas Dixon, The Invention of Altruism: Making Moral Meanings in Victorian Britain (Oxford: Oxford University Press, 2008), 129–180 (describes Darwin’s ethics in terms largely consilient with my own, but with little focus on Darwin’s sources); Eric Charmetant, “Darwin et l’éthique: Une rencontre précoce, un chantier toujours ouvert,” Archives de Philosophie 73, no. 1 (2010): 93–118 (downplays the role of competition in Darwin’s ethics, but reads it as deriving from William Paley and James Mackintosh, rather than Smith); George Levine, Darwin Loves You: Natural Selection and the Re-enchantment of the World (Princeton: Princeton University Press, 2006) (acknowledges competition and struggle in Darwin, but emphasizes Darwin’s celebration of wonder and enchantment); Robert J. Richards, Darwin and the Emergence of Evolutionary Theories of Mind and Behavior (Chicago: University of Chicago Press, 1987) (reads Darwin’s ethics as based on evolutionary naturalism and explores the connection between Darwin and James).
24. “Economy, n.,” OED Online (Oxford University Press. n.d.), accessed March 2016.
25. Thomas Hobbes, Leviathan (Oxford: Clarendon Press, 1909), 2.23.4.
26. Daniel Waterland, Eight Sermons Preach’d at the Cathedral Church of St. Paul (Cambridge: Corn. Crownfield, 1720), 268.
27. Kenelm Digby, Two Treatises (London: John Williams, 1645), 103; Samuel Collins, A Systeme of Anatomy (Savoy: Thomas Newcomb, 1685), 419.
28. Carolus Linnaeus, “The Oeconomy of Nature,” in Miscellaneous Tracts Relating to Natural History, Husbandry, and Physick, trans. Benjamin Stillingfleet (London: R. and J. Dodsley, 1762), 39–129, at 39.
29. Erasmus Darwin, The Botanic Garden (New York: T. & J. Swords, 1791).
30. Alexander von Humboldt and Aimé Bonpland, Personal Narrative of Travels to the Equinoctial Regions of the New Continent during the Years 1799–1804, 7 vols., trans. Helen Maria Williams (London: Longman, 1814), 2:71, 3:148 and 155, 4:158, 5:1.93, 6:1.390.
31. Charles Lyell, Principles of Geology, 3 vols. (London: John Murray, 1830–33). For more on pre-Darwinian naturalists on the “economy of nature,” see Trevor Pearce, “‘A Great Complication of Circumstances’—Darwin and the Economy of Nature,” Journal of the History of Biology 43 (2010): 493–528, at 495–501.
32. Janet Browne, Charles Darwin: Voyaging (Princeton: Princeton University Press, 1995), 83.
33. C. Darwin, “Notebook B,” in Charles Darwin’s Notebooks, 1836–1844, ed. Paul H. Barrett et al. (Cambridge: Cambridge University Press, 1987), 1.
34. E. Darwin, Zoonomia, 2 vols. (London: J. Johnson, 1794).
35. C. Darwin, Charles Darwin’s Beagle Diary, ed. R. D. Keynes (Cambridge: Cambridge University Press, 2001), 443, 42.
36. C. Darwin, Origin, 310, 282, 292.
37. C. Darwin, Charles Darwin’s Zoology Notes & Specimen Lists from H.M.S. Beagle, ed. Richard Keynes (Cambridge: Cambridge University Press, 2000), 138.
38. C. Darwin, Beagle Diary, 360.
39. C. Darwin, “Darwin’s Ornithological Notes,” ed. Nora Barlow, Bulletin of the British Museum (Natural History) Historical Series 2, no. 7 (1963): 220, 239.
40. C. Darwin, “Darwin’s Notebooks on Transmutation of Species, Part VI, Pages Excised by Darwin,” ed. Sir Gavin de Beer, Bulletin of the British Museum (Natural History) Historical Series 3, no. 5 (1960): 163.
41. Robert C. Stauffer, “Ecology in the Long Manuscript Version of Darwin’s ‘Origin of Species’ and Linnaeus’ ‘Oeconomy of Nature,’” Proceedings of the American Philosophical Society 104, no. 2 (1960): 239.
42. C. Darwin, The Foundations of The Origin of Species, ed. Francis Darwin (Cambridge: Cambridge University Press, 1909); C. Darwin, Origin.
43. C. Darwin, “‘Books to Be Read’ and ‘Books Read’ Notebook,” 3v, CUL-DAR119, Darwin Papers, Cambridge University Library; Dugald Stewart, “Account of the Life and Writings of Adam Smith,” in Smith, Essays on Philosophical Subjects (London: Cadell and Davies, 1795), ix–xcv.
44. Margaret Schabas, The Natural Origins of Economics (Chicago: University of Chicago Press, 2006), 91–92, 101.
45. C. Darwin, Origin, 115–16.
46. Henri Milne-Edwards, Histoire naturelle des crustacés (Paris: Roret, 1834), 1:5. “[L]a vie de l’individu résulte de l’ensemble d’élémens hétérogènes tous plus ou moins dépendans les uns des autres.”
47. Augustin Pyramus de Candolle, “Géographie botanique,” in Dictionnaire des sciences naturelles, ed. Frédéric Cuvier, vol. 18 (Paris: Levrault, 1820), 387.
48. Lyell, Principles of Geology, 2:141. For more on de Candolle, Lyell, and “places,” see Pearce, “A Great Complication,” 501–6.
49. C. Darwin, Origin, 115–16.
51. Darwin, “Books Notebook”; Schweber, “Darwin and the Political Economists,” 196, 265–75.
52. Thomas Robert Malthus, An Essay on the Principle of Population, 2 vols. (London: John Murray, 1826).
53. C. Darwin, Autobiography, 120.
54. Milne-Edwards, Histoire naturelle des crustacés, 1:5–6.
55. Schweber, “Darwin and the Political Economists,” 212–13.
56. The question of whether it is possible to reconcile the two works is known as “das Adam Smith Problem,” a term coined in August Oncken, “The Consistency of Adam Smith,” The Economic Journal 7 (1897): 443–50. For the current status of the debate, see Leonidas Montes, “Das Adam Smith Problem: Its Origins, the Stages of the Current Debate, and One Implication for Our Understanding of Sympathy,” Journal of the History of Economic Thought 25 (2003): 63–90. I need not enter into the debate here.
57. Smith, Moral Sentiments, 1.1.1. Citations to Moral Sentiments are to book, chapter, and paragraph.
58. Ibid., 1.1.2.
59. Ibid., 1.1.5.
60. Ibid., 1.1.28.
61. See, e.g., ibid., 3.1.76 and 2.1.27n.
62. Ibid., 1.1.37.
63. See, e.g., ibid., 1.1.43, 2.2.14, 3.1.83, 3.1.90.
64. The extent of this congruence is sharply debated among Smith scholars. Some believe that Smith’s account “veers dangerously close to relativism.” See, e.g., Samuel Fleischacker, On Adam Smith’s Wealth of Nations: A Philosophical Companion (Princeton: Princeton University Press, 2004), 52. Others believe that the impartial spectator brings a significant measure of objectivity to moral judgments. See, e.g., Geoffrey Sayre-McCord, “Sentiments and Spectators: Adam Smith’s Theory of Moral Judgment,” in The Philosophy of Adam Smith, ed. Vivienne Brown and Samuel Fleischacker (London: Routledge, 2010), 124–44. I am interested less in the subtleties of Smith’s theory than in how Darwin interpreted and refigured it; accordingly, I take no position on this debate.
65. Smith, Moral Sentiments, 2.1.27n.
67. Ibid., 4.1.14. See also, e.g., ibid., 1.1.33, 4.1.16, 4.1.22. Smith occasionally seems to place more weight on utility, as when defending a death sentence for a sentinel who falls asleep at his post and so endangers the community. Ibid., 2.2.25. However, Smith generally regards utility as a consequence of moral actions rather than a reason to judge actions as moral. See, e.g., Charles L. Griswold Jr., Adam Smith and the Virtues of Enlightenment (Cambridge: Cambridge University Press, 1999), 135–46, 200, and James R. Otteson, Adam Smith’s Marketplace of Life (Cambridge: Cambridge University Press, 2002), 58–64, 250.
68. C. Darwin, “Books Notebook,” 12v; C. Darwin, “Notebook M,” in Barrett, Charles Darwin’s Notebooks, 108; C. Darwin, “Notebook N,” in Barrett, Charles Darwin’s Notebooks, 184.
69. James Mackintosh, Dissertation on the Progress of Ethical Philosophy, 2nd ed. (Edinburgh: Adam and Charles Black, 1837), 234–36.
70. C. Darwin, “Books Notebook,” 12v.
71. C. Darwin, “Notebook M,” 108.
72. C. Darwin, “Books Notebook,” 12v.
73. C. Darwin, “Notebook M,” 108.
74. C. Darwin, “Books Notebook,” 12v.
75. C. Darwin, “Notebook C,” in Barrett, Charles Darwin’s Notebooks, 196–97.
76. C. Darwin, “Notebook M,” 29.
77. C. Darwin, “Notebook E,” in Barrett, Charles Darwin’s Notebooks, 49. Emphasis in original.
78. C. Darwin, “Old and Useless Notes,” in Barrett, Charles Darwin’s Notebooks, 30–30v.
79. Ibid., 30. Emphasis in original.
80. C. Darwin, “Notebook M,” 132e. Emphasis in original.
81. Smith, Moral Sentiments, 2.1.27n.
82. C. Darwin, The Descent of Man (London: John Murray, 1871), 1:81 and 1:81n17.
83. Ibid., 1:32.
84. Ibid., 1:135. See also 1:34 and 1:105.
85. C. Darwin, The Descent of Man, 2nd ed. (London: John Murray, 1874), 99.
86. C. Darwin, Descent (1871), 1:71–72.
87. Ibid., 1:81.
88. Ibid., 1:92.
89. C. Darwin, Descent (1874), 98n5.
92. Darwin, Descent (1871), 1:94.
93. Browne, Charles Darwin: Voyaging, 198–99.
94. C. Darwin, Origin, 5.
95. C. Darwin, Descent (1871), 1:73.
96. C. Darwin, Origin, 202–3.
97. Francis E. Abbot, “To Charles Darwin,” 3 March 1874, CUL-DAR159.5, Darwin Papers, Cambridge University Library. I thank the Manuscripts Department at Cambridge University for permission to quote from the letter and the editors of the Darwin Correspondence Project, who provided a transcript of the letter.
98. Abbot, “Darwin’s Theory of Conscience: Its Relation to Scientific Ethics,” The Index, March 12, 1874, 122–25, at 123.
99. C. Darwin, “To Francis E. Abbot,” 30 March 1874, Papers of F. E. Abbot, 1841–1904, Named Correspondence, 1857–1903, box 44, HUG 1101, Harvard University Archives. I thank the Harvard University Archives for permission to quote from the letter and the editors of the Darwin Correspondence Project, who provided a transcript of the letter.
100. William Darwin, “To Francis Darwin,” June 2, [1883–1887?], CUL-DAR198.109, Darwin Papers, Cambridge University Library.
101. Ignas K. Skrupskelis, “Evolution and Pragmatism: An Unpublished Letter of William James,” Transactions of the Charles S. Peirce Society 43, no. 4 (Fall 2007): 745–52, at 749–50.
102. Ibid., 750.
103. William James, “The Moral Philosopher and the Moral Life,” International Journal of Ethics 1, no. 3 (April 1891): 330–54, at 335.
104. James, Pragmatism (New York: Longmans, Green, and Co., 1907), 171. Emphasis in original.
105. James, “The Moral Philosopher and the Moral Life,” 337.