The exact specification of the changes in the arrangement of the subject-matter, necessitated by the dedication to Varro, will be more conveniently deferred till we come to the fragments of the second edition preserved by Nonius and others. Roughly speaking, the following were the contents of the four books. Book I.: the historico-philosophical exposition of Antiochus' views, formerly given by Hortensius, now by Varro; then the historical justification of the Philonian position, which Cicero had given in the first edition as an answer to Hortensius[304]. Book II.: an exposition by Cicero of Carneades' positive teaching, practically the same as that given by Catulus in ed. I.; to this was appended, probably, that foretaste of the negative arguments against dogmatism, which in ed. 1. had formed part of the answer made by Cicero to Hortensius. Book III.: a speech of Varro in reply to Cicero, closely corresponding to that of Lucullus in ed. 1. Book IV.: Cicero's answer, substantially the same as in ed. 1. Atticus must have been almost a κωφον προσωπον. I may here notice a fact which might puzzle the student. In some old editions the _Lucullus_ is marked throughout as _Academicorum liber IV_. This is an entire mistake, which arose from a wrong view of Nonius' quotations, which are always from the _second_ edition, and can tell us nothing about the constitution of the _first_. One other thing is worth remark. Halm (as many before him had done) places the _Academica Priora_ before the _Posteriora_. This seems to me an unnatural arrangement; the subject-matter of the _Varro_ is certainly prior, logically, to that of the _Lucullus_. * * * * * M. TULLII CICERONIS ACADEMICORUM POSTERIORUM LIBER PRIMUS. * * * * *