Personal Identity (Fall 1999) / Notes / Practical consequences of reductionism

Practical consequences of reductionism

11 November

Extreme vs.moderate claims

Given how important questions about personal identity are to judgments about rationality and ethics, you would think that a view as radical as Parfit's Reductionism would have some pretty serious implications in these areas.

There are two basic approaches to these alleged changes: extreme and moderate.

The Extreme Claim about self-interest goes like this: if there is no further fact of personal identity, then there are no self-interested reasons to care about any future person in the way that I care about my future now. There are similar extreme claims about the various kinds of ethical issues in which personal identity is involved.

The various Moderate Claims held only that some of our thinking about rationality and ethics has to change if we move from the Further Fact View to Reductionism.

I said that I thought the Extreme Claim (and its variants) are only interesting as part of a reductio strategy: if Reductionism were true, we'd have no self-interested reasons to care about future persons, we obviously do have self-interested reasons to care about future persons, therefore, Reductionism is false (see Butler, p. 102 and Reid, pp. 116-117; both in Perry, Personal Identity).

If one tried to say that both Reductionism and the Extreme Claim are true (really true, not just assumed to be true for the sake of argument, as in the previous paragraph), then I think there would be trouble.

After all, if Reductionism is true, it's always been true. Nothing about the way your life seems to proceed would have changed: from the 'inside,' everything's the same. You have as much reason now for caring in a self-interested way about the future as you ever did; you have as much reason to anticipate the unpleasant feelings for the next two weeks of a cold that you know will last for that long (and hence the same reasons for seeking a cure). Perhaps that's "None"; perhaps you've never actually had any self-interested reasons concerning the future and your anticipation of future pain and pleasure has always been illusory. But that's hard to believe; the thought that I'm closely related to a particular future person is still quite overpowering, even when I do entertain the possibility that Reductionism is true. Perhaps that's because I'm very closely R-related to a future person. But the fact remains that his interests stand out for me in a way that no one else's do. So I, myself, have trouble believing both Reductionism and the Extreme Claim.

By the same token, I find the Moderate Claim more palatable, as a description of how my thinking should change were Reductionism (really) true. Some of my judgments should change, others will get a stronger philosophical basis. But not everything will change.

So what should change?

Reductionism doesn't give you a lot of guidance. Look at those cases on ethics. In its moderate version, Reductionism tells you that it may make sense to describe a case as involving two persons, or, weaker still, that it may make sense to think about a case as if it involved two different persons.

Well, when should we think that there are two different persons and when should we think there is just one? Reductionism itself doesn't help much here. At best, it clears the deck of the Further Fact view. But as far as making more subtle particular judgments about personal identity, it doesn't do much.

One thing it does is redirect apparently fruitless philosophical quests for answers. When does a person's life begin or end? Sometimes, there's no definite answer, so we can't hope for an answer to questions about abortion, say, by looking there. Perhaps we'd come to a different answer about this problem if we accepted the Reductionist view.


According to Olson, the bodily criterion can take a similiar position about the beginning and ending of a person's life. Olson says we're all human animals - from our beginnings as fetuses to our biological deaths. For a significant part of our careers as animals, we're persons, that is, intelligent, conscious, thinking beings (he accepts Locke's definition of a person). But that's compatible with saying that there is a gray area in which it's not obvious whether a given animal is a person or not. Neat. Of course, that means that Olson's animalism can conflict with the Further Fact intuitions that I find so compelling. But no one's perfect. I've decided: I'm going to teach Olson sometime soon. I really like that book.

Another thing Reductionism does is resolve ideas that we have already that seem to be in tension with one another. We are inclined to say that someone who has undergone a great change in character is a different person. We certainly treat such a person differently: if a previously vicious criminal sees the light, repents, and starts acting like a saint, we're much less inclined to punish that person. What's the point? More to the point, it's like the (former) criminal is a different person.

Of course, some might say, he's not literally a different person. He's just qualitatively different.

But, we might say, fortified with Reductionist arguments, it can still make sense to describe him as a different person. If your only argument against doing so is "it's not literally true," then we're unimpressed. There's really nothing to "being literally the same person" except Relation-R. We can say he's the same person in one sense -- he's got some R-relations to his criminal past and the same body -- but we can also legitimately say he's a different person in another sense -- he's got a new personality. If there were just one further fact about personal identity, maybe we couldn't say that. But there isn't. So we can.

That's not to say this is something you would have to say if you accepted Reductionism. It's just something that would be more defensible to say were Reductionism true. Since many of us are inclined to say it already, perhaps Reductionism conforms to our common sense thought a little more closely than it appears.

Page and author information

This page was originally posted on 11/12/99; 11:05:58 AM and was last built on 11/12/99; 11:45:36 AM.

Copyright by Michael J. Green, except where noted.

How to contact me: email, mailing address, phone number, and office hours.


Previous page: Reductionism vs. the Further Fact View

List of all pages in this section

Site outline