Soc. Thirst again is a destruction and a pain, but the filling with moisture
 of that which was dried up is a pleasure. Then, too, the unnatural dissolution and disintegration we experience through heat are a pain, but the natural restoration and cooling are a pleasure. Pro. Certainly. Soc. And the unnatural hardening of the moisture in an animal through cold is pain; but the natural course of the elements returning to their place and separating is a pleasure. See, in short, if you think it is a reasonable statement that whenever in the class of living beings,
 which, as I said before, arises out of the natural union of the infinite and the finite, that union is destroyed, the destruction is pain, and the passage and return of all things to their own nature is pleasure. Pro. Let us accept that; for it seems to me to be true in its general lines. Soc. Then we may assume this as one kind of pain and pleasure arising severally under the conditions I have described? Pro. Let that be assumed. Soc. Now assume within the soul itself the anticipation of these conditions,
 the sweet and cheering hope of pleasant things to come, the fearful and woful expectation of painful things to come. Pro. Yes, indeed, this is another kind of pleasure and pain, which belongs to the soul itself, apart from the body, and arises through expectation. Soc. You are right. I think that in these two kinds, both of which are, in my opinion, pure, and not formed by mixture of pain and pleasure, the truth about pleasure will be made manifest,
 whether the entire class is to be desired or such desirability is rather to be attributed to some other class among those we have mentioned, whereas pleasure and pain, like heat, cold, and other such things, are sometimes desirable and sometimes undesirable, because they are not good themselves, though some of them sometimes admit on occasion the nature of the good. Pro. You are quite right in saying that we must track our quarry on this trail. Soc. First, then, let us agree on this point: If it is true,
 as we said, that destruction is pain and restoration is pleasure, let us consider the case of living beings in which neither destruction nor restoration is going on, and what their state is under such conditions. Fix your mind on my question: Must not every living being under those conditions necessarily be devoid of any feeling of pain or pleasure, great or small? Pro. Yes, necessarily. Soc. Have we, then, a third condition,
 besides those of feeling pleasure and pain? Pro. Certainly. Soc. Well then, do your best to bear it in mind; for remembering or forgetting it will make a great difference in our judgement of pleasure. And I should like, if you do not object, to speak briefly about it. Pro. Pray do so. Soc. You know that there is nothing to hinder a man from living the life of wisdom in this manner. Pro. You mean without feeling pleasure or pain? Soc. Yes, for it was said, you know, in our comparison of the lives that he who chose the life of mind and wisdom was to have no feeling of pleasure, great or small. Pro. Yes, surely, that was said. Soc. Such a man, then, would have such a life; and perhaps it is not unreasonable, if that is the most divine of lives. Pro. Certainly it is not likely that gods feel either joy or its opposite. Soc. No, it is very unlikely; for either is unseemly for them. But let us reserve the discussion of that point
 for another time, if it is appropriate, and we will give mind credit for it in contending for the second place, if we cannot count it for the first. Pro. Quite right. Soc. Now the other class of pleasure, which we said was an affair of the soul alone, originates entirely in memory. Pro. How is that? Soc. We must, apparently, first take up memory, and perception even before memory, if these matters are to be made clear to us properly. Pro. What do you mean? Soc. Assume that some of the affections of our body are extinguished in the body before they reach the soul, leaving the soul unaffected, and that other affections permeate both body and soul and cause a vibration in both conjointly and in each individually. Pro. Let us assume that. Soc. Shall we be right in saying that the soul forgets those which do not permeate both, and does not forget those which do? Pro. Yes, certainly. Soc. Do not in the least imagine that when I speak of forgetting I mean that forgetfulness arises in this case; for forgetfulness is the departure of memory, and in the case under consideration memory has not yet come into being; now it is absurd to speak of the loss of that which does not exist and has not yet come into being, is it not? Pro. Certainly. Soc. Then just change the terms. Pro. How?