After confessing to have a “passionate predilection” for the law of love over the law of greed, and cautioning his readers to be on guard because of his “one-sidedness,” Peirce considered the different theories of evolution for their “logical affinities.” To some extent Peirce recapitulated his discussion of evolution in “The Architecture of Theories,” but from a different standpoint. In “Evolutionary Love,” Peirce identified three principal kinds of evolution and a number of sub-varieties. The main varieties were evolution by fortuitous variation, evolution by mechanical necessity, and evolution by creative love. Darwinian evolution is evolution by fortuitous variation, or chance, but with a secondary action required to “secure advance in a definite direction.” The secondary action is “struggle for existence” in which greed is the motivating desire. Although chance is the critical factor in Darwinian evolution, the success of nineteenth-century physicists in bringing non-conservative processes into the domain of mechanical law by means of the statistical method satisfied the prevailing nominalist scientific community that the non-conservative action of organic development must also be fundamentally mechanical. Peirce named evolution by fortuitous variation tychastic evolution, or tychasm.
The second principal kind of evolution was evolution by mechanical necessity. There are different varieties of evolution of this general kind, including August Weismann’s theory that all biological forms are “mechanical resultants of the heredity from two parents,”116 and the theory of geologists, like Clarence King, that evolution is the result of cataclysmic changes in the environment of the evolving organisms (other geologists point to environmental factors but think cataclysms unnecessary). For Weismann, there is an inner necessity at work and for King it is an external necessity, but for all varieties of evolution of this kind, chance is not a factor. Peirce named evolution by mechanical necessity anancastic evolution, or anancasm.
The third kind of evolution was Lamarckian evolution, or evolution by the transmission to offspring of acquired characteristics (“hypertrophies or atrophies which have affected individuals early in their lives”). According to Peirce, Lamarckians recognize that some transmitted characteristics, or “modifications of form,” may have been initially due to mechanical causes, but he identified “the straining of endeavor” and “exercise” as the key factors. “Now, endeavor, since it is directed toward an end, is essentially psychical, even though it be sometimes unconscious; and the growth due to exercise, as I argued in my last paper, follows a law of a character quite contrary to that of mechanics.” Peirce was tempted to say that Lamarckian evolution is “evolution by the force of habit,” but habit is “mere inertia, a resting on one’s oars, not a propulsion.” Yet habit “serves to establish the new features, and also to bring them into harmony with the general morphology and function of the animals and plants to which they belong.” Peirce’s discussion of Lamarckian evolution focuses mainly on the development of mind; he even remarks at one point that the “first step in the Lamarckian evolution of mind is the putting of sundry thoughts into situations in which they are free to play.” This seems compatible with the current view that Lamarckian evolution is not as applicable to biological evolution as it is to social evolution—but Peirce’s objective idealism may provide the necessary theoretical bridge to span these realms. Peirce finally pointed out, what had surely become obvious to any careful reader, that his “account of Lamarckian evolution coincides with the general description of the action of love.” Peirce considered this kind of evolution to be “evolution by creative love” and called it agapastic evolution, or agapasm. Related names that are probably more familiar to students of Peirce’s philosophy are tychism, anancism, and agapism, which name the doctrines “that absolute chance, mechanical necessity, and the law of love, are severally operative in the cosmos.”
In the final section of “Evolutionary Love,” Peirce pointed out that there is no sharp line of demarcation between the three kinds of evolution and that the main questions were “whether three radically different evolutionary elements have been operative” and “what are the most striking characteristics of whatever elements have been operative.” He briefly considered these questions from the standpoint of “the historical development of thought.” After identifying the main features of tychastic, anancastic, and agapastic developments of thought, Peirce gave historical examples supporting the conclusion that these different kinds of evolution really are operative in the world and revealing some interesting characteristics, such as that what distinguishes anancasm from agapasm “is its purposelessness.” Peirce’s description of the agapastic development of thought stressed the key role that sympathy plays and that the power of sympathy depends on the continuity of mind. Agapasm and synechism are closely linked. A telling conclusion Peirce drew from this exercise was that “all of the greatest achievements of mind have been beyond the powers of unaided individuals.”
Although one might read the conclusion of “Evolutionary Love” as a satisfactory culmination of Peirce’s cosmological series, it was not intended as such, and Peirce always regretted having to end it so abruptly. His lengthy “Reply to the Necessitarians” (W9, sel. 38), a rejoinder to Carus’s attack on his tychism, appeared in the Monist in July 1893, but was not the sixth paper he had in mind. “Man’s Glassy Essence” included a statement suggesting that Peirce expected to consider in a sixth paper how the number and distribution of regions of positive and negative potential surrounding atoms would determine their valency. Early in 1893, when Peirce was negotiating with Hegeler to publish a book of his philosophical papers, he planned to include twenty papers, the final six being the five Monist papers followed by chapter 20, a general sketch of the theory of the universe—maybe what he intended for the sixth paper. In 1895, Peirce wrote to Russell that had Hegeler kept his promise to allow him another article, “the 6th article, which would have been the keystone of the whole, would have related to that branch which I variously call Second intentional Logic, Objective Logic, & Pure Rhetoric. By this I mean the doctrine of the Evolution of thought.” Finally, ten years later, in 1905 in another Monist paper, “What Pragmatism Is,” Peirce described what he had planned for the concluding article of his cosmology series (EP2: 345):
Had a purposed article concerning the principle of continuity and synthetizing the ideas of the other articles of a series in the early volumes of The Monist ever been written, it would have appeared how, with thorough consistency, that theory involved the recognition that continuity is an indispensable element of reality, and that continuity is simply what generality becomes in the logic of relatives, and thus, like generality, and more than generality, is an affair of thought, and is the essence of thought. Yet even in its truncated condition, an extra-intelligent reader might discern that the theory of those cosmological articles made reality to consist in something more than feeling and action could supply, inasmuch as the primeval chaos, where those two elements were present, was explicitly shown to be pure nothing. Now, the motive for alluding to that theory just here is that in this way one can put in a strong light a position which the pragmaticist holds and must hold, whether that cosmological theory be ultimately sustained or exploded, namely, that the third category,—the category of thought, representation, triadic relation, mediation, genuine Thirdness, Thirdness as such,—is an essential ingredient of reality, yet does not by itself constitute reality, since this category (which in that cosmology appears as the element of habit) can have no concrete being without action, as a separate object on which to work its government, just as action cannot exist without the immediate being of feeling on which to act.
Thinking back on his Monist series around 1906, Peirce regarded it as “a first crude” try at a modern scientific metaphysics, no longer up-to-date in all its detail but still “serving to indicate just what sort of a thing is wanted.”117 Peirce’s assessment of the series is pretty close to the settled view of those who over the years have studied it. As the details of the science become less relevant, the radical and landmark nature of some of his main ideas has become all the more apparent. Peirce’s