49 But, you will say, there are good men also in the world—wise, upright, of faultless and purest morals. We raise no question as to whether there ever were any such, in whom this very integrity which is spoken of was in nothing imperfect. Even if they are very honourable men, and have been worthy of praise, have reached the utmost height of perfection, and their life has never wavered and sunk into sin, yet we would have you tell us how many there are, or have been, that we may judge from their number whether a comparison has been made which is just and evenly balanced. One, two, three, four, ten, twenty, a hundred, yet are they at least limited in number, and it may be within the reach of names. But it is fitting that the human race should be rated and weighed, not by a very few good men, but by all the rest as well.
For the part is in the whole, not the whole in a part; and that which is the whole should draw to it its parts, not the whole be brought to its parts. For what if you were to say that a man, robbed of the use of all his limbs, and shrieking in bitter agony, was quite well, because in one little nail he suffered no pain? Or that the earth is made of gold, because in one hillock there are a few small grains from which, when dissolved, gold is produced, and wonder excited at it when formed into a lump? The whole mass shows the nature of an element, not particles fine as air; nor does the sea become immediately sweet, if you cast or throw into it a few drops of less bitter water, for that small quantity is swallowed up in its immense mass; and it must be esteemed, not merely of little importance, but even of none, because, being scattered throughout all, it is lost and cut off in the immensity of the vast body of water.
Source: Against the Heathen (New Advent)