Darwin proved that this law was true of all the lower animals and showed that it was responsible for the evolution of the lower apes into anthropoid apes, and that it could account, theoretically, for a possible evolution of anthropoid apes into man. But in "The Descent of Man" he argued that the law of natural selection ceased when man became an intelligent being. Thereafter, he said, man's own efforts worked against those of nature. Instead of letting the unfit of his race die, civilization began to protect and preserve them. The result was that nature's tendency to make all living beings more and more sturdy was set aside by man's own conviction that mere sturdiness was not the thing most to be desired. From this Darwin argued that if two tribes of human beings lived side by side, and if, in one of them, the unfit were permitted to perish, while in the other there were many "courageous, sympathetic and faithful members, who were always ready to warn each other of danger, and to aid and defend one another"--that in such a case, the latter tribe would make the most progress, despite its concerted effort to defy a law of nature. Darwin's disciples agreed with him in this and some of them went to the length of asserting that civilization, in its essence, was nothing more or less than a successful defiance of this sort.[13] Herbert Spencer was much troubled by the resultant confusion and as one critic puts it,[14] the whole drift of his thought "appears to be inspired by the question: how to evade and veil the logical consequence of evolutionarism for human existence?" John Fiske, another Darwinian, accepted the situation without such disquieting doubt. "When humanity began to be evolved," he said, "an entirely new chapter in the history of the universe was opened. Henceforth the life of the nascent soul came to be first in importance and the bodily life became subordinated to it."[15] Even Huxley believed that man would have to be excepted from the operation of the law of natural selection. "The ethical progress of society," he said, "depends, not on imitating the cosmic process and still less on running away from it, but in combating it." He saw that it was audacious thus to pit man against nature, but he thought that man was sufficiently important to make such an attempt and hoped "that the enterprise might meet with a certain measure of success."[16] And the other Darwinians agreed with him.[17]