"The nerve-tissue," said an acute physiologist, "is never precisely the same in two men; the blood of no two men is precisely alike; the milk of no two women is identical in composition--they all vary (within certain limits), and sometimes the variation is considerable. It is in this that depends what we call the difference of 'temperament,' which makes one twin so unlike his brother, and makes the great variety of the human race." "Give Professor Owen part of an old bone or a tooth, and he will on the instant draw you the whole animal, and tell you its habits and propensities. What professor has ever yet been able to classify the wondrous variety of human character? How very limited as yet the nomenclature! We know there are in our moral dictionary the religious, the irreligious, the virtuous, the vicious, the prudent, the profligate, the liberal, the avaricious, and so on to a few names, but the comprehended varieties under these terms--their mixtures, which, like colors, have no names--their strange complexities and intertwining of virtues and vices, graces and deformities, diversified and mingled, and making individualities--yet of all the myriads of mankind that ever were, not one the same, and scarcely alike; how little way has science gone to their discovery, and to mark their delineation! A few sounds, designated by a few letters, speak all thought, all literature, that ever was or will be. The variety is infinite, and ever creating a new infinite; and there is some such mystery in the endless variety of human character." Cicero gives an account of a man who could distinguish marks of difference amongst eggs so well, that he never mistook one for another; and, having many hens, could tell which laid a particular egg. Socrates asked Menon what virtue was? "There is," said Menon, "the virtue of a man and of a woman, of a magistrate and of a private person, of an old man and of a child." "Very well," said Socrates, "we were in quest of virtue, and thou hast brought us a whole swarm." "What," asks the great French essayist, "have our legislators got by culling out a hundred thousand particular cases, and annexing to these a hundred thousand laws? The number holds no manner of proportion with the infinite diversity of human actions; the multiplication of our inventions will never arrive at the variety of examples; add to them a hundred times as many more; it will not, nevertheless, ever happen, that, of events to come, there shall any one fall out that, in this great number of thousands of events so chosen and recorded, shall find any one to which it can be so exactly coupled and compared, that there will not remain some circumstance and diversity which will require a variety of judgment."