Personal Identity and Continuity
Mark Johnson summarizes “psychological reductionism,” brilliantly, as follows: it is the view, he says “that truths about personal identity have as necessary and sufficient conditions statements about the holding of relations of mental continuity and connectedness. Connectedness involves the holding of direct psychological connections, such as the persistence of beliefs and desires, the connection between and intention and the later act in which the intention is carried out, and the connection between an experience and a memory of that experience.” (Metaphysics: An Anthology, 394)
Let’s spell this out. Person B at t2 is person A at t1 if and only if
(a) some beliefs and desires of A are found in B;
(b) those habits that are in B but not in A have been created in or acquired by B by means of A’s own actions;
(c) B remembers the state of his character in A and the steps A took to modify this character to become B.
Consider the following situation. A prays to God and says: “Change me into something other than what I am, such as B.” Can God modify A in an instant at 0 cost to him? Certainly not, because existing habits, like everything that is, have a certain authority; they have a power to endure, and they insist upon remaining what they are barring overwhelming force. So, if God were to change A into B in this manner, He would do violence to A’s nature. And grace is never violent but builds upon nature. The connection between A and B must therefore take the form “goal sought by A — goal accomplished in B.” A must first come to love his future self B more than his present self A. Then he must figure out how to attain B’s habits or virtues and, through them, acts. Finally, A must overcome the inertia of his own habits, their “authority,” their innate tendency to persist, and bend them to his will.
The crucial thing here is that A himself initiates and follows through with his metamorphosis into B. If his love, knowledge, or abilities are lacking somewhere so that A falters in his way toward B yet ought to become him, they may be enhanced via friendly help. But no one can do A’s job for him — A must demonstrate through action and struggle which has disutility of labor that he wants to be B no matter the cost.
And just as A keeps his eyes on the prize of being B as his goal while he is working on himself to become B, so B must also keep A and A’s exertions in memory in order for there to be continuity between them. Hence (c). There must be a contemplation of success, of victory by B over whatever deficiencies prevailed in A. Given these three individually necessary and jointly sufficient links, then, B can be said to have maintained his identity with A despite perhaps even drastic changes in his personality. Note that this does not contradict my previous suggestion that X is the same as Y if the four causes of X are identical with the four causes of Y. There is a world of difference between identity of things and personal identity of human beings. B is not identical to A, but person B is nevertheless the same person as A. Update. Identity through time, like trans-world identity, requires sortals. A and B, if to be considered the same, must be the same F. In our case B is not the same Dmitry, say, as A but the same person.
Now it is possible that some external event changes you. Then seemingly you don’t apply any effort to actuate the change. (For example, it may come in the form of an epiphany. I was once troubled by the thought that I did not love enough, did not have enough charity. And then it occurred to me: “Nobody loves enough!” And at that very moment my heart was healed.) True, but you allow it to take place and presumably love the change and come to know the “new you.” That is enough. There is no reason why some good things can’t be free. Just as action-toward-rest is required to morph from A into B, so action-while-at-rest is required to remain B. The latter is attended by self-love (of B) and self-knowledge (of B). But proper action-while-at-rest is assured if B was brought about in the manner outlined above, that is, by A’s and the intermediaries between A and B’s own self-directing actions which may include allowing externally induced changes to take effect. (If you know yourself as Bk and how to transition to Bk+1 via means Mk, then you know Bk+1 or, in this case, know yourself as Bk+1. It follows that at the end of the process you will know yourself as B.)
Johnson goes on in describing this view: “The identity over time of any particular human body or brain plays no strictly indispensable role in the identity of a particular person over time. Any particular human body or brain is just one causal means among others for the holding of the relations of psychological continuity and connectedness which constitute a particular person’s survival.” I agree completely. Though Johnson thinks otherwise, the role of the brain has been greatly exaggerated.