  Aristotle is less explicit about the understanding of categories as concepts. In Categories generally he does not speak about how things are conceived; rather, he speaks about how things are called or how they are. At the same time, from what he says elsewhere about signification and the way we think, it is not unreasonable to surmise that he also thinks of categories as concepts of some kind. For example, at the beginning of On Interpretation, he claims that “spoken sounds are symbols of affections [or concepts] in the soul, and written marks symbols of spoken sounds. And just as written marks are not the same for all men, neither are spoken sounds. But what these are in the first place sounds of–affections of the soul–are the same for all; and what these affections are likenesses of–actual things–are also the same” (16a 4–8).