...monetary exchanges have interesting things in common; Gresham's law, if true, says what one of these interesting things is. But what is interesting about monetary exchanges is surely not their commonalities under physical description. A natural kind like a monetary exchange could turn out to be co-extensive with a physical natural kind; but if it did, that would be an accident on a cosmic scale.

I take it that computational processes are both symbolic and formal. They are symbolic because they are defined over representations, and they are formal because they apply to representations, in virtue of (roughly) the syntax of the representations.

...there are special sciences not because of the nature of our epistemic relation to the world, but because of the way the world is put together: not all natural kinds (not all the classes of things and events about which there are important, counterfactual supporting generalizations to make) are, or correspond to, physical natural kinds.

There are lots of cases where we know more about how the world works than we do about how we know how it works. That's no paradox. Understanding the structure of galaxies is one thing, understanding how we understand the structure of galaxies is quite another. There isn't the slightest reason why the first should wait on the second and, in point of historical fact, it didn't. This bears a lot of emphasis; it turns up in philosophy practically everywhere you look.

I rather doubt that life has a meaning. If I thought perhaps it did, and I wanted to find out what its meaning is, I don't imagine I'd ask someone whose credentials consist of a PhD in philosophy.

Suppose that the organism is given the problem of determining the analysis of a stimulus at a certain level of representation - e.g., the problem of determining which sequence of words a given utterance encodes. Since, in the general case, transducer outputs underdetermine perceptual analyses, we can think of the solution of such problems as involving processes of nondemonstrative inference. In particular, we can think of each input system as a computational mechanism which projects and confirms a certain class of hyputheses on the basis of a certain body of data.

...if it isn't literally true that my wanting is causally responsible for my reaching, and my itching is causally responsible for my scratching, and my believing is causally responsible for my saying . . . If none of that is literally true, then practically everything I believe about anything is false and it's the end of the world.