Having determined what a work of art is, our author goes on to study the social conditions under which works of art are produced; and he concludes that the general character of a work of art is determined by the state of intellect and morals in the society in which it is executed. There is, in fact, a sort of moral temperature which acts upon mental development much as physical temperature acts upon organic development. The condition of society does not produce the artist's talent; but it assists or checks its efforts to display itself; it decides whether or not it shall be successful And it exerts a "natural selection" between different kinds of talents, stimulating some and starving others. To make this perfectly clear, we will cite at some length Taine's brilliant illustration. The case chosen for illustration is a very simple one,--that of a state of society in which one of the predominant feelings is melancholy. This is not an arbitrary supposition, for such a time has occurred more than once in human history; in Asia, in the sixth century before Christ, and especially in Europe, from the fourth to the tenth centuries of our era. To produce such a state of feeling, five or six generations of decadence, accompanied with diminution of population, foreign invasions, famines, pestilences, and increasing difficulty in procuring the necessaries of life, are amply sufficient. It then happens that men lose courage and hope, and consider life an evil. Now, admitting that among the artists who live in such a time, there are likely to be the same relative numbers of melancholy, joyous, or indifferent temperaments as at other times, let us see how they will be affected by reigning circumstances. Let us first remember, says Taine, that the evils which depress the public will also depress the artist. His risks are no less than those of less gifted people. He is liable to suffer from plague or famine, to be ruined by unfair taxation or conscription, or to see his children massacred and his wife led into captivity by barbarians. And if these ills do not reach him personally, he must at least behold those around him affected by them. In this way, if he is joyous by temperament, he must inevitably become less joyous; if he is melancholy, he must become more melancholy.