And I will now explain in a few words the things which are inseparably connected with this sure and solid opinion.
There is no mistake with respect to the ends themselves of good and evil, that is to say, with respect to pleasure and pain; but men err in these points when they do not know what they are caused by. But we admit that the pleasures and pains of the mind are caused by the pleasures and pains of the body. Therefore I grant what you were saying just now, that if any philosophers of our school think differently (and I see that many men do so, but they are ignorant people) they must be convicted of error. But although pleasure of mind brings us joy, and pain causes us grief, it is still true that each of these feelings originates in the body, and is referred to the body; and it does not follow on that account that both the pleasures and pains of the mind are not much more important than those of the body. For with the body we are unable to feel anything which is not actually existent and present; but with our mind we feel things past and things to come. For although when we are suffering bodily pain, we are equally in pain in our minds, still a very great addition may be made to that if we believe that any endless and boundless evil is impending over us. And we may transfer this assertion to pleasure, so that that will be greater if we have no such fear.
This now is entirely evident, that the very greatest pleasure or annoyance of the mind contributes more to making life happy or miserable than either of these feelings can do if it is in the body for an equal length of time. But we do not agree that, if pleasure be taken away, grief follows immediately, unless by chance it happens that pain has succeeded and taken the place of pleasure; but, on the other hand, we affirm that men do rejoice at getting rid of pain even if no pleasure which can affect the senses succeeds. And from this it may be understood how great a pleasure it is not to be in pain. But as we are roused by those good things which we are in expectation of, so we rejoice at those which we recollect. But foolish men are tortured by the recollection of past evils; wise men are delighted by the memory of past good things, which are thus renewed by the agreeable recollection. But there is a feeling implanted in us by which webury adversity as it were in a perpetual oblivion, but dwell with pleasure and delight on the recollection of good fortune. But when with eager and attentive minds we dwell on what is past, the consequence is, that melancholy ensues, if the past has been unprosperous; but joy, if it has been fortunate.