ARISTOTLE'S PRIOR AND POSTERIOR ANALYTICS

RELATION OF PRIOR TO POSTERIOR ANALYTICS IIwere written after the Prior Analytics, and that reference (I) ismore naturally explained by supposing that the Prior A nalyticswas written before and as a preliminary to the Posterior Analytics.The other references prove nothing except that Aristotle meantthe Prior A nalytics to precede the Posterior in the order ofinstruction.There is, however, another way in which we can consider theexplicit references from one book to another. Many of Aristotle'sworks, taken in pairs, exhibit cross-references backward to oneanother; and this must be taken to indicate either that the twoworks were being written concurrently, or that a book which waswritten earlier was later supplied with references back to the otherbecause it was placed after it in the scheme of teaching-which iswhat Solmsen supposes to have happened to the Posterior Analyticsin relation to the Prior. But it is noticeable that no such crossreferencesoccur here. The references in the Prior A nalytics to thePosterior are all forward; those in the Posterior A nalytics to thePrior are all backward. If the order of writing did not correspondto the order of teaching, we should expect some traces of the orderof writing to survive in the text; but no such traces do survive.This is an argument from silence, but one which has a good dealof weight.We must now turn to consider whether, apart from actualreferences, the two works give any indication of the order inwhich they were written. It may probably be said without fearof contradiction that none of the contents of the Prior Analyticscertainly presuppose the Posterior. Let us see whether any ofthe contents of the Posterior Analytics presuppose the Prior.The scrutiny, involving as it does an accumulation of smallpoints, is bound to be rather tedious; but it will be worth makingit if it throws any light on the question we are trying tosolve. Broadly speaking, the nature of the evidence is thatthe Posterior A nalytics repeatedly uses in a casual way termswhich have been explained only in the Prior, and assumes doctrineswhich only there have been proved. If this can be madegood, the conclusion is that before the Posterior Analytics waswritten either the Prior must have been written, or an earlierversion of it which was so like it that Solmsen's contentionthat the philosophical logic of the Posterior A nalytics was anearlier discovery than the formal logic of the Prior falls to theground.