The general facts about the world will enable our program to decide to call a travel agent to find out how to get to Boston. He proceeds by arguing that the mental qualities of a hypothetical artificial man could not be defined physically even if we knew the details of its physical structure. One sense of Davidson's statement does not require the arguments he gives. Any information processing system that can be constructed of one kind of element can be constructed of any other. Therefore, physics tells us nothing about what information processes exist in nature or can be constructed.
Computer science is no more reducible to physics than is psychology.
However, Davidson also argues that the mental states of an organism are not describable in terms of its physical structure, and I take this to assert also that they are not describable in terms of its construction from logical elements. I would take his arguments as showing that mental qualities don't have what I have called first order structural definitions. I don't think they apply to second order definitions. However, the present paper emphasizes criteria for ascribing particular mental qualities to particular machines rather than the general proposition that mental qualities may be ascribed. I think that the chess programs Dennett discusses have more limited mental structures than he seems to ascribe to them.