Political and national decadence is Mr. Balfour's theme, and we note first that here is a contemporary thinker, not unread in recent biology, including the work of Weismann, who is prepared to make use of the idea that societies are inherently mortal, as individuals are. One wonders when we shall be rid of this pernicious instance of the argument from analogy, which is already much more than two thousand years old. Next it may be noticed that, though Mr. Balfour has deliberately discussed the idea of natural selection, he has been led wholly astray from its true relation to the question under discussion by reason of falling into the common error which Sir E. Ray Lankester has recently exposed, as Huxley did several decades ago. Mr. Balfour conceives natural selection to issue from the struggle for existence between species or societies. It has already been pointed out that the all-important natural selection is not between species or societies but within them. The struggle for existence is fought out mainly between the immature individuals of any species or society. Its issue determines the survivors for parenthood and the future. Mr. Balfour must have read Professor Ray Lankester's recent Romanes Lecture in which all this is so clearly shown, but he has unfortunately retained the popular conception of natural selection as acting between species or societies, and has in consequence failed, I will not say to find, but even to discuss in any adequate measure, the theory of racial and national decadence, defined in the preceding chapter. He merely discusses “competition between groups of communities,” and rightly finds it inadequate to account for the great tragedies of history. There follows a passage which may be heartily assented to, on the very grounds on which the entire lecture may be welcomed, namely, that it suggests the inadequacy of the common explanations of national decadence advanced by historians. Says Mr. Balfour:-- “It is in vain that historians enumerate the public calamities which preceded, and no doubt contributed to, the final catastrophe. Civil dissensions, military disasters, pestilences, famines, tyrants, tax-gatherers, growing burdens, and waning wealth--the gloomy catalogue is unrolled before our eyes, yet somehow it does not in all cases wholly satisfy us: we feel that some of these diseases are of a kind which a vigorous body politic should easily be able to survive, that others are secondary symptoms of some obscurer malady, and that in neither case do they supply us with the full explanation of which we are in search.”