Personal Identity

Class notes for 1-3 February

Main points

I began with an observation about the relationship among the chapters we have been discussing. 1.4.6 parallels 1.4.3: both are about the belief in the identity and simplicity of, respectively, minds and bodies. 1.4.5 parallels 1.4.4: both are about what, respectively, minds and bodies are made of.

1.4.6 has four basic parts:

  1. Setting up the problem (¶¶ 1-5)
  2. Why we believe in the identity of things despite changes (¶¶ 6-14)
  3. Why we believe in the identity of our minds despite changes (¶¶ 15-21)
  4. Why we believe in the simplicity of our minds (¶ 22)

We spent most of our time on 1 February talking about the second part, the belief in the identity of plants, animals and other changing things.

We began class on 3 February with a discussion of a set of alternatives to Hume’s treatment of the third point, the explanation of the belief in the identity of one’s own mind over time.

Identity in general

We began with a story that Hume has been telling for some time: the belief in the identity of something over time involves confusing different patterns of perceptions with what I called the “identity pattern.” (see,,, The story is that the transition from one perception to the next in the non-identity patterns feels similar to the transition from one perception to the next in the identity pattern. That is why we confuse the different patterns with one another.

There are two points here. The first is to offer a deflationary explanation of why people (usually philosophers) believe in substances or other “unknown and mysterious” things: our imaginations make up fictions to cover the contradiction between our belief that the thing has remained the same and the evident differences among our perceptions.

The second point is that our beliefs about identity are determined by the workings of our minds rather than by the nature of objects. Hume gives several examples where the objects have obviously changed — mountains are added to them, for example — but we nonetheless believe they have remained the same. He explains our beliefs as the products of our psychology and perspective: we believe it has remained the same so long as we expect the changes, the changes feel insignificant, or the changes seem small to us. Take the two together and that is his case for concluding that most of our beliefs about identity are merely the results of the way our minds work.

Our discussion concerned a different argument for the same conclusion that Hume did not make. Megan pointed out that nothing about the nature of the thing forces us to think about rivers rather than water molecules. So why do we expect, as Hume says we do, that a river is the kind of thing whose parts are constantly changing?

Peter noted that our interests play a role that Hume didn’t acknowledge. We have good reason for caring about rivers that we do not have for caring about particular water molecules. Among other things, talking about rivers enables us to give directions. It is also very useful for drawing causal inferences (see

Personal Identity

We talked about the relationship between Hume’s positive explanation of the belief in personal identity over time and Locke’s account.

I noted that we do not vulgarly distinguish between perceptions and objects (see 1.4.2) and, since that is so, it will be very hard for Hume to tell a persuasive story about how we get the belief in personal identity out of our perceptions.

Suppose I had grown up in a brown room; I would have a perfectly resembling series of perceptions of a brown room. I can see how that would lead me to believe in the existence of a brown room. But why would it lead me to believe anything about myself or my mind? Where am I in a perception of a brown room?

Less direct attempts

Having cast doubt on Locke and Hume’s attempt to get the belief in personal identity from directly surveying perceptions, we turned to less direct methods: these are alternatives, paths that Hume did not take.

I said that I think that part of the story ought to involve other people: I learn that I have a distinct, separate mind by observing that other people behave as if they have different perceptions in their minds than the ones in mine. Learning to lie, for example, depends on knowing that. That probably isn’t enough to get one to an idea of the self with the characteristics that Hume describes: identical despite changes and simple despite complexity. But it has to be part of the story, in my opinion.

On the 3rd of February, we began with a suggestion Charlie and Will made, namely that there has to be more to the mind than just perceptions — the imagination, the understanding, our propensities, and so on — and that this other stuff might help to answer Hume’s question.

Discussion revealed that it is not always obvoius that Hume had just one question. In particular, it’s important to distinguish between explaining our belief in personal identity and explaining what personal identity consists in, that is, what it really involves whether we know it or not. The Charlie-Will story seems more plausible for the latter than for the former, in my opinion.

Finally, I pointed back to §9 in Locke. There’s something there about what it is like to have conscious thoughts that neither of these two indirect strategies (mine and the Charlie-Will one) really comes to terms with. It’s not just that there’s a chair, it’s that I see the chair. Similarly, my memories are of my seeing things; that goes beyond just knowing what happened in the past. Some of our thoughts, especially those involving the senses and feelings, do seem to involve ourselves in some very difficult to explain sense. Locke does about as well as anyone. So, despite my reservations, I conceded that Hume and Locke seem to have been onto something that neither indirect version handles nearly as well.