ABSTRACT
In Chapter 4, the text of 7b15–8a12 is presented in full, after which each of the five arguments offered there in support of the thesis of the exceptional character of the pairs of relatives knowledge/knowable and perception/perceptible in what regards natural simultaneity is reconstructed. In an interim section, some aspects of the key concepts involved in these arguments, namely knowledge and knowable, perception and perceptible, are clarified. Finally, in the third section, the five arguments are analysed and shown to have problems of various kinds, with the result that they all fail to prove that thesis. In this discussion, the claims put forth in the previous two chapters are mobilised. The main conclusion of Chapter 4 is that (contra Aristotle) all relatives, including the pairs claimed to be exceptional, reciprocate as to implication of existence, insofar as reciprocation as to implication of existence is inferred from the conjunction of the correlativity and reciprocity of relatives, which are definitional to them. However, this does not mean that they are all naturally simultaneous, because reciprocation as to implication of existence is just one of the two conditions of natural simultaneity, mutual causal non-dependence being the other, which some relatives arguably do not satisfy.
