There is another way in which practical reasoning can lead one to adopt new ends. Sometimes one adopts an end so that things that one has already done or plans to do can gain significance as means toward the end that one now adopts. This is how some people choose careers—so that their earlier training will not be wasted. The typical teacher of physics, for example, did not originally study the subject with the purpose of becoming a physics teacher. He studied the subject because it interested him or perhaps because it was a required subject. Later he decided to become a teacher of physics; at that point he was able to see his earlier study as part of the means by which he is able to become a physics teacher—and that is part of his reason for becoming a physics teacher: so that his earlier study will not have been wasted.
It is true that he enjoys physics (let us suppose), so he is choosing a career that will allow him to do something that he enjoys doing. But that is only one consideration. It is also relevant that in becoming a physics teacher he gives significance to his earlier study and to that extent helps to unify his life. If he had chosen instead to do something else, he might always have felt some unhappiness over his decision, even if he fully enjoyed his life. His training in physics might in that case have had no significance—it would have been wasted. It would have lost connection with his later life, a connection that could have helped to give his life unity. In the same way, someone who is musical or athletic in his youth will often feel unhappy if he does not continue those activities as he grows older.
People create their lives, at least to some extent. They adopt purposes which give their lives meaning. But they do not adopt these purposes ahead of time—only after the fact. To choose a career is for many people to drift into a career. Past acts done for other reasons assume a pattern in the light of ends adopted only now.
We adopt ends that help to rationalize and give significance to what we have been and are doing—not only in large decisions, as in choosing careers, but even in our smallest and most insignificant acts. A dramatic illustration of this occurs when someone who has been hypnotized is told that later, after he "comes out of it," at a given signal, he is to open a window. When he does later open the window and is asked why, he will be found to have constructed some appropriate end that will rationalize what he is doing. This is no mere curiosity, worthy of interest only as a parlor trick. It represents an important aspect of rationality, an aspect that promotes stability in one's plans and allows one to assume that one's long range plans will be carried out. For in the midst of them, one will be strongly motivated to continue so as not to waste what has gone before. In the midst of some minor activity one may forget what one intends to be doing, but one will often then reconstruct an end on the basis of what is being done at the moment, and one will finish—simply for the sake of finishing what one is doing. One does something because that was what one was doing. Otherwise, one's earlier activities would be pointless.
The same idea keeps one going in more serious activities. A student continues in graduate school, for example, because he has gone this far already and, if he stops now, the earlier years would amount to nothing. This is, of course, not always for the best. Some people irrationally continue careers, political or religious activities, or their families because they do not want to have to count what they have been doing so far as a waste of time. The aspect of practical reasoning that we are now discussing is not its only aspect and it should not always prevail. But it is an important aspect, and an account of practical reasoning that ignores it is incomplete.
Practical reasoning is, like theoretical reasoning, holistic. In practical reasoning, one seeks a conception of one's life that is both explanatorily coherent and coherent with one's desires. One can increase coherence by adopting means to already existing ends—but that is not the only way. One can also increase coherence by adopting new ends, either because the adoption of those ends will help get one something previously wanted, or because adopting those ends gives a significance to things one has already done or plans to do.
(Gilbert Harman, "Practical Reasoning," Review of Metaphysics 29 [March 1976]: 431-63, at 461-3)
Keith Burgess-Jackson, J.D., Ph.D. 