bring down a category or universal upon it, the category or universal called Being. But Being is an idea. Being is not identical or commensurate with my sensation, it embraces infinitely more. Being is not my sensation, but something different from it; and being something different from sensation, it properly obtains a different name; it is called an idea. We thus see that in the simplest and earliest operation of thinking, we are forced, whether we will or no, into the region of ideas, and that thinking is impossible without them. Thinking is, in fact, nothing else than the application of ideas or universals to the sensible phenomena of the universe. And the theory which declares this to be the case (as Plato's theory does) is not so much a theory as a fact; a fact which it is impossible to dispute or deny, without falling into the grossest absurdities and contradictions.
21. To this argument proving the necessity of ideas, the objection may perhaps be raised that it is a mere truism, equivalent to the assertion that it is impossible to think without having thoughts, a proposition which no one would ever dream of denying, but which does not advance us far in our pursuit of truth. I answer that the argument does amount to that proposition, but it also amounts to a great deal more. It not only shows that we cannot think without having thoughts or ideas, but it moreover explains what ideas are; it sets them forth as universals, and thus essentially distinguishes them from
