School, we know from the fact that Diogenes begins his exposition of the first Trope in a way similar to that of Sextus.[4] His illustrations are, however, few and meagre compared with those of Sextus, and the scientific facts used by both of them may mostly be found in other authors of antiquity given in a similar way.[5] The logical result of the reasoning used to explain the first Trope, is that we cannot compare the ideas of the animals with each other, nor with our own; nor can we prove that our ideas are more trustworthy than those of the animals.[6] As therefore an examination of ideas is impossible, any decided opinion about their trustworthiness is also impossible, and this Trope leads to the suspension of judgment regarding external objects, or to [Greek:  epoche.][7]

    [1] Hyp..  I. 54.

    [2] Hyp..  I. 55.

    [3] Hyp..  I. 55-59.

    [4] Diog.  IX. 11, 79-80.

    [5] Pappenheim Erlauterung Pyrr.  Grundzuege Par. 41.

    [6] Hyp.  I. 59.

    [7] Hyp.  I. 61.

After reaching this conclusion, Sextus introduces a long chapter to prove that animals can reason.  There is no reference to this in Diogenes, but there is other testimony to show that it was a favourite line of argument with the Sceptics.[1] Sextus, however, says that his course of reasoning is different from that of most of the Sceptics on the subject,[2] as they usually applied their arguments to all animals, while he selected only one, namely the dog.[3] This chapter is full of sarcastic attacks on the Dogmatics, and contains the special allusion to the Stoics as the greatest opponents of the Sceptics, which has been before referred to.[4]

Sextus claims with a greater freedom of diction than in some apparently less original chapters, and with a wealth of special illustrations, that the dog is superior to man in acuteness of perception,[5] that he has the power of choice, and possesses an art, that of hunting,[6] and, also, is not deprived of virtue,[7] as the true nature of virtue is to show justice to all, which the dog does by guarding loyally those who are kind to him, and keeping off those who do evil.[8] The reasoning power of this animal is proved by the story taken from Chrysippus, of the dog that came to a meeting of three roads in following a scent.  After seeking the scent in vain in two of the roads, he takes the third road without scenting it as a result of a quick process of thought, which proves that he shares in the famous dialectic of Chrysippus,[9] the five forms of [Greek:  anapodeiktoi logoi,] of which the dog chooses the fifth.  Either A or B or C, not A or B, therefore C.

    [1] Hyp.  I. 238.

    [2] Compare Brochard Op. cit. 256.

    [3] Hyp.  I. 62-63.

    [4] Hyp.  I. 65.