My talk is called What is a Substance? Substance is a very important topic in metaphysics.

Indeed, for metaphysicians like Aristotle, it's the central and dominant topic.

Unfortunately, metaphysicians disagree not only about the nature of substance,

they also discuss different things

under the label substance.

It's easy to get tangled up.

And it takes careful analysis

to just make sure that you're making sense.

Putting it differently,

if you aren't careful,

you can be so far off track

that you aren't even wrong.

Okay. You can be so far off track that you aren't even wrong. In this talk, I'm going to lay out a few different senses of substance,

but I'm going to focus on just two of them and really on just one of them.

Another way I'm going to restrict my remarks is by mostly talking just about the views

of Aristotle and, surprise, surprise, Aquinas. Near the end, however, I will see some things

about relatively recent approaches to substance so that you can see more clearly what's special

about the Aristotelian tomistic approach.

I've just said that metaphysicians discuss different things under the label substance,

but actually that's misleading. Aquinas and Aristotle never ever use the word substance.

After all, English is not a language that they use.

It's fun to think about the fact that I couldn't resist sticking this in here. Aquinas could have

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