 Aristotle uses ‘(prote) ousia’ not only as a count-noun but as a mass term. (He generally writes ‘ousia’ without qualification when he believes that the context will make it clear that he means ‘prote ousia’.) For example, he not only asks questions like “Is Socrates a (prote) ousia?” and “What is a (prote) ousia”?, but questions like “What is the (prote) ousia of Socrates?” and “What is (prote) ousia?” (Which question he is asking sometimes has to be inferred from the context, since there is no indefinite article in Greek.) In the count-noun sense of the term, Aristotle identifies at least some (protai) ousiai with ta hupokeimena or “underlying things”. Socrates, for example, is a hupokeimenon in that he “lies under” the in rebus universals under which he falls and the accidents that inhere in him. ‘To hupokeimenon’ has an approximate Latin equivalent in ‘substantia’, “that which stands under”. (Apparently, “to stand under” and “to lie under” are equally good metaphorical descriptions of the relations a thing bears to its qualities and accidents.) Owing both to the close association of (protai) ousiai and hupokeimena in Aristotle's philosophy and to the absence of a suitable Latin equivalent of ‘ousia’ ‘substantia’ became the customary Latin translation of the count-noun ‘(prote) ousia’.