[149] For it is the peculiar province of philosophy to inquire what a conjunction, what a noun, what a verb, what a common noun, what a particular noun, what is deficient in a speech, what is superfluous, what is an affirmative, what an interrogative, what an indirect question, what is a comprehensive expression, what is a supplicatory form of address. For this is a science which has been compounded for the purpose of the investigation of independent propositions, and axioms, and categorems.