In the first place, they endeavour to show that many things can appear to exist, which in reality have no existence; when minds are moved to no purpose by things which do not exist, in the same manner as by things that do. For when you say (say they) that some visions are sent by God, as those, for instance, which are seen during sleep, and those also which are revealed by oracles, and auspices, and the entrails of victims, (for they say that the Stoics, against whom they are arguing, admit all these things,) they ask how God can make those things probable which appear to be false; and how it is that He cannot make those appear so which plainly come as near as possible to truth? Or if He can likewise make those appear probable, why He cannot make the others appear so too, which are only with great difficulty distinguished from them? And if He can make these appear so, then why He cannot also make those things appear so which are absolutely different in no respect whatever?
In the next place, since the mind is moved by itself,—as those things which we picture to ourselves in thought, and those which present themselves to the sight of madmen or sleeping men declare,—is it not, say they, probable that the mind is also moved in such a manner, that not only it does not distinguish between the perceptions, as to whether they be true or false, but that there really is no difference between them? As, for instance, if any men of their own accord trembled and grew pale, on account of some agitation of mind, or because some terrible object came upon them from without, there would be no means of distinguishing one trembling and paleness from the other, nor indeed would there be any difference between the external and internal alarm which caused them.
Lastly, if no perceptions are probable which are false, then we must seek for other principles; but if they are probable, then why may not one say the same of such as are not easily distinguished from one another? Why not also of such as have actually no difference at all between them? Especially when you yourselves say that the wise man when enraged withholds himself from all assent, because there is no distinction between his perceptions which is visible to him.
XVI. Now on all these empty perceptions Antiochus brought forward a great many arguments, and one whole day was occupied in the discussion of this subject. But I do not