 Boethius, for his part, held that Ø is a possible state of affairs, human beings are contingent beings, and so the necessity operator in (1) makes the proposition false in all circumstances, and the argument that man cannot possibly be or be conceived of without animal fails because it is not necessary for man to be or to be conceived of at all. Boethius agrees that in a world that does contain at least one human, the human essence is the cause of the inherence of the predicate animal in man, and hence of the truth of 