But as the cause of perturbations is now discovered, 162for all of them arise from the judgment or opinion, or volition, I shall put an end to this discourse. But we ought to be assured, since the boundaries of good and evil are now discovered, as far as they are discoverable by man, that nothing can be desired of philosophy greater or more useful than the discussions which we have held these four days. For besides instilling a contempt of death, and relieving pain so as to enable men to bear it, we have added the appeasing of grief, than which there is no greater evil to man. For though every perturbation of mind is grievous, and differs but little from madness, yet we are used to say of others when they are under any perturbation, as of fear, joy, or desire, that they are agitated and disturbed; but of those who give themselves up to grief, that they are miserable, afflicted, wretched, unhappy. So that it doth not seem to be by accident, but with reason proposed by you, that I should discuss grief, and the other perturbations separately; for there lies the spring and head of all our miseries; but the cure of grief, and of other disorders, is one and the same in that they are all voluntary, and founded on opinion; we take them on ourselves because it seems right so to do. Philosophy undertakes to eradicate this error, as the root of all our evils: let us therefore surrender ourselves to be instructed by it, and suffer ourselves to be cured; for while these evils have possession of us, we not only cannot be happy, but cannot be right in our minds. We must either deny that reason can effect anything, while, on the other hand, nothing can be done right without reason, or else, since philosophy depends on the deductions of reason, we must seek from her, if we would be good or happy, every help and assistance for living well and happily.
Marcus Tullius Cicero (Cicero's Tusculan Disputations Also, Treatises On The Nature Of The Gods, And On The Commonwealth)