[5]. There is nothing distinctive about this which might enable us to determine its connection with the dialogue. Probably Zeno is the person who serius adamavit honores.
[6]. The changing aspects of the same thing are pointed to here as invalidating the evidence of the senses.
[7]. This passage has the same aim as the last and closely resembles Lucullus [105].
[8]. The fact that the eye and hand need such guides shows how untrustworthy the senses are. A similar argument occurs in Luc. [86]. Perpendiculum is a plumb line, norma a mason's square, the word being probably a corruption of the Greek γνωμων (Curt. Grundz p. 169, ed. 3), regula, a rule.
[9]. The different colours which the same persons show in different conditions, when young and when old, when sick and when healthy, when sober and when drunken, are brought forward to prove how little of permanence there is even in the least fleeting of the objects of sense.
[10]. Urinari is to dive; for the derivation see Curt. Grundz p. 326. A diver would be in exactly the position of the fish noticed in Luc. [81], which are unable to see that which lies immediately above them and so illustrate the narrow limits of the power of vision.
[11]. Evidently an attempt to prove the sense of smell untrustworthy. Different people pass different judgments on one and the same odour. The student will observe that the above extracts formed part of an argument intended to show the deceptive character of the senses. To these should probably be added fragm. [32]. Fr. [19] shows that the impossibility of distinguishing eggs one from another, which had been brought forward in the Catulus, was allowed to stand in the second edition, other difficulties of the kind, such as those connected with the bent oar, the pigeon's neck, the twins, the impressions of seals (Luc. [19], [54]), would also appear in both editions. The result of these assaults on the senses must have been summed up in the phrase cuncta dubitanda esse which Augustine quotes from the Academica Posteriora (see fragm. [36]).
BOOK III.
[12]. This forms part of Varro's answer to Cicero, which corresponded in substance to Lucullus' speech in the Academica Priora The drift of this extract was most likely this: just as there is a limit beyond which the battle against criminals cannot be maintained, so after a certain point we must cease to fight against perverse sceptics and let them take their own way. See another view in Krische, p. 62.
[13]. Krische believes that this fragment formed part of an attempt to show that the senses were trustworthy, in the course of which the clearness with which the fishes were seen leaping from the water was brought up as evidence. (In Luc. [81], on the other hand, Cic. drew an argument hostile to the senses from the consideration of the fish.) The explanation seems to me very improbable. The words bear such a striking resemblance to those in Luc. [125] (ut nos nunc simus ad Baulos Puteolosque videmus, sic innumerabilis paribus in locis esse isdem de rebus disputantis) that I am inclined to think that the reference in Nonius ought to be to Book IV. and not Book III., and that Cic., when he changed the scene from Bauli to the Lucrine lake, also changed Puteolosque into pisciculosque exultantes for the sufficient reason that Puteoli was not visible from Varro's villa on the Lucrine.