DIADUMENUS. Nor is this the strangest thing you will find in their doctrine; but their being of opinion that virtue and happiness, when present, are frequently not perceived by him who enjoys them, nor does he discern that, having but a little before been most miserable and foolish, he is of a sudden become wise and happy. For it is not only childish to say that he who is possessed of wisdom is ignorant of this thing alone, that he is wise, and knows not that he is delivered from folly; but, to speak in general, they make goodness to have very little weight or strength, if it does not give so much as a feeling of it when it is present. For according even to them, it is not by nature imperceptible; nay, even Chrysippus in his books of the End expressly says that good is sensible, and demonstrates it also, as he thinks. It remains then, that by its weakness and littleness it flies the sense, when being present it is unknown and concealed from the possessors. It were moreover absurd to imagine that the sight, perceiving those things which are but a little whitish or inclining to white, should not discern such as are white in perfection; or that the touch, feeling those things which are but warm or moderately hot, should be insensible of those that are hot in the highest degree. And yet more absurd it is, that a man who perceives what is commonly according to Nature —as are health and good constitution of body—should yet be ignorant of virtue when it is present, which themselves hold to be most of all and in the highest degree according to Nature. For how can it but be against sense, to conceive the difference between health and sickness, and yet so little to comprehend that between wisdom and folly as to think the one to be present when it is gone, and possessing the other to be ignorant that one has it? Now because there is from the highest progress a change made to felicity and virtue, one of these two things must of necessity follow; either that this progress is not vice and infelicity, or that virtue is not far distant from vice, nor happiness from misery, but that the difference between good and evil is very small and not to be perceived by sense; for otherwise they who have the one for the other could not be ignorant of it.