from it; for they say that we regard as certain, those things which always produce similar impressions on the senses, those which are the offspring of habit, or which are established by the laws, and those too which give pleasure or excite wonder. And they prove that the reasons opposite to those on which our assent is founded are entitled to equal belief.
IX. The difficulties which they suggest, relating to the agreement subsisting between what appears to the senses, and what is comprehended by the intellect, divide themselves into ten modes of argument, according to which the subject and object of our knowledge is incessantly changing. And these ten modes Pyrrho lays down in the following manner.
The first relates to the difference which one remarks between the sentiments of animals in respect of pleasure, and pain, and what is injurious, and what is advantageous; and from this we conclude, that the same objects do not always produce the same impressions; and that the fact of this difference ought to be a reason with us for suspending our judgment.
For there are some animals which are produced without any sexual connexion, as those which live in the fire, and the Arabian Phœnix, and worms. Others again are engendered by copulation, as men and others of that kind; and some are composed in one way, and others in another; on which account they also differ in their senses, as for instance, hawks are very keen-sighted; dogs have a most acute scent.
It is plain, therefore, that the things seen produce different impressions on those animals which differ in their power of sight. So, too, young branches are eagerly eaten by the goat, but are bitter to mankind; and hemlock is nutritious for the quail, but deadly to man; and pigs eat their own dung, but a horse does not.
The second mode refers to the nature and idiosyncracies of men. According to Demophon, the steward of Alexander used