Conclusion Immanuel Kant, in the “Paralogisms of Pure Reason,” describes the paradigmatic rational psychologistic account of personhood with all of its most salient features: [S]ubstance, merely as object of inner sense, yields [geben] the concept of immateriality; as simple substance, that of incorruptibility. Its identity as intellectual substance yields personality; all three of these components together, spirituality. The relations of the substance to objects yields commerce with bodies; and as so related it therefore presents thinking substance as the principle of life in matter; that is, as soul (anima) and as the basis of animality; and animality as limited by spirituality presents immortality. (CPR A345/B403) We can now see that Kant is describing accurately Leibniz’s account. We saw, first of all, that Leibniz, along with another famous rational psychologist, Descartes, holds that once a person, always a person. This might seem a less than interesting view, until we realize that neither Conway nor Locke, perhaps the most famous personal identity theorist of all, agree. We also saw that it is not clear in Leibniz whether I began as a non-person. We continued by arguing against several scholars that Leibniz consistently defends the view that we just are simple immaterial substances that endure through time. But not just any kind of substance; we saw that there is a psychological component to personhood: to be persons we must possess the attributes of memory, self-consciousness, intelligence, and rationality. We are, in Kant’s words, “intellectual substances.” We saw that although Leibniz appears to concede to Locke that if there existed thinking machines they would be moral agents and thus retain moral identity over time, this concession is only apparent. To do so would be to abandon certain of his most important metaphysical and theological principles. Yet Leibniz does concede something of significance to Locke: we ought to treat thinking machines as if they were moral agents. (Ironically, such knowledge of Leibniz’s theory gives us good reason to think that the third paralogism of pure reason as described by Kant is not Leibnizian. For Leibniz does not accept the major premise, which seems to express the proposition that if something is conscious of the numerical identity of itself at different times then it is a person. But, we have seen, this essentially Lockean proposition is not acceptable to Leibniz. Please see Appendix B for more.) Strictly speaking, Leibniz tells us, we are causally independent of one another, but we are also moral agents, participating and interacting in the same world and responsible for our deeds that affect the lives of others. Leibniz’s resolution of 118 Conclusion 119 these conflicting theses, as we saw, is to explain that it is through our bodies that we communicate, socialize, and reward and punish each other. Moreover, we also saw that moral agents require bodies. This state of “animality” persists also into the next life. Finally, we saw that Leibniz’s account of personhood figures prominently in his doctrine of meaningful immortality. Leibniz argues that the state of survival offered by Plato, Descartes, and Spinoza, among others, would be meaningless to us. They do not secure over time what matters in survival, namely, memory or the knowledge of what we have been. And, in Spinoza’s case, we do not even retain substantial identity which also rationally matters in survival, according to Leibniz. Appendix A On Hume Mental predicates require a subject. What would it mean to deny this proposition? For one, we might get Hume’s view: when we say that someone is the “same person,” we are actually saying that distinct perceptions (that is, mental events, according to Hume) bear either a causal relation or a close resemblance among themselves in such a way that they appear unified. Our idea of identity, hence, is really, part and parcel, our idea of unity. And, it is we ourselves who “impose” our own idea of identity upon ourselves, for it is we who alone have any access to the unity of our perceptions, that is, consciousness. We might imagine that a similar view is reflected in Leibniz’s own words. For example, Leibniz writes: “It is this continuity or interconnection [liaison] of perceptions which make someone really the same individual” (A vi, 6, 239/NE II, 27, §13).1 Not only does Leibniz’s notion of perception share something in common with Hume’s (both use ‘perception’ as their most general term for mental phenomena), but identity of individuals (here, Leibniz is speaking specifically of individual persons) is seen in terms of unity. But lest we be misled into thinking otherwise, there are significant differences between these two views. Suffice it to say that Leibnizian unity is not Humean unity. For Leibniz, this unity which identical individuals display among their perceptions is genuine in the sense that distinct perceptions which are related causally, lawfully, or phenomenologically derive from the same source, a power, nature, or faculty in the individual itself. Hence, strictly speaking this unity does not constitute the identity of the individual, rather it points to an identity. What unifies something metaphysically is the power itself (GP ii, 372/L 599, Letter to Des Bosses [30 April 1709]). Successive states belong to the same individual if and only if they are produced by the same power or individual nature. Hume, on the other hand, thinks that individual perceptions, whether related causally, lawfully, phenomenologically, or not at all, are distinct entities. They are not caused by one and the same individual nature; that is, the existence of causally related perceptions does not presuppose the existence of a diachronically identical thing (i.e., a subject) that has these perceptions. One might also get the impression that Locke agrees with Hume that mental predicates do not require a subject. Yes, Locke writes of “the same consciousness uniting those distant Actions into the same Person …” (E II, 27, §10). But, as with Leibniz, Locke tells us that it was a substance (or substances) that “contributed to [the] production” of those “distant Actions,” which include both physical and mental events. Locke seems to hold that what does the thinking for us is a substance of some kind. 120 Appendix 121 So neither Leibniz nor Locke allow subject-less mental predicates. I think this is precisely what explains why Leibniz and Locke are willing to consider substance as the condition of personal identity, or at least as the condition that gives rise to the unity of consciousness or perception. So even though Locke sometimes show impatience with the traditional metaphysical debate over the category of substance—substance-talk is for “Children” (E II, 23, §2)— nevertheless, he is seriously willing to consider whether substantial identity is relevant to personal identity or whether in general substance plays a role in judgments of personal identity. According to Leibniz, persons are not modes or relations of things. Leibniz would reason as follows, I think: (1) persons must necessarily have mental predicates ascribed to them; (2) mental predicates require a subject ; (3) only beings or things can genuinely be subjects; therefore, (4) persons are beings or things. Yet however Leibniz would argue for proposition 4, it seems clear that he accepts it. Leibniz says that each of us “continues to exist as really the same substance, the same physical I” (A vi, 6, 238/NE II, 27, §11) and in §14 calls a person “[a]n immaterial being or spirit.” Again, it is useful to contrast Hume’s view with the view I have attributed to Leibniz. According to Hume, persons belong to the world of imagination, not reality; a person “is nothing but a heap or collection of different perceptions, united together by certain relations” (T 207). This view seems at odds with proposition 4. Since the self is supposed to be an object which endures (although it may underlie change), any impression of self must always be the same, thinks Hume; however, “[t]here is no impression constant and invariable. Pain and pleasure, grief and joy, passions and sensations succeed each other. It cannot therefore, be from any of these perceptions, or from any other that the idea of self is deriv'd; and consequently there is no such idea” (T 251f). Or, this conclusion might be derived from another direction. Hume holds that all genuine metaphysical entities are epistemically available or observable distinct from perceptions. But selves are not epistemically available or observable in the above manner—“I never can catch myself at any time without a perception, and never can observe any thing but the perception” (T 252). Hence, selves are not genuine metaphysical entities. Hume writes that “were all my perceptions remov’d by death, and cou’d I neither think, nor feel, nor see, nor love, nor hate … I shou’ be entirely annihilated. … If any one upon serious and unprejudic’d reflexion, thinks he has a different notion of himself, I must confess I can reason no longer with him” (T 252). Leibniz also thinks that persons are not conventional beings; objects that have no real essence or individual nature, as it were.2 In other words, according to Leibniz, ascriptivism regarding the self is false. Whether there are persons is not a matter that can be settled by establishing conventions or by merely stipulating them into existence. Though it is time we made an important distinction: this rejection of ascriptivism concerns natural persons, not artificial persons. Artificial persons are by definition conventional or stipulative beings. Blackstone makes the distinction clear: “Natural persons are such as the God of nature formed us; 122 Appendix artificial are such as are created and devised by human laws for the purposes of society and government.”3 A current example of an artificial person is the Microsoft Corporation, a legal entity that has been on trial off and on for several years in the United States of America.