Observe that history, so conceived, must needs compare faculty with desire, achievement with expectation, fulfilment with design. And no moralist has ever found pleasure in the comparison. The vanity of human wishes and the brevity of human life are immemorial themes of lamentation; nor do they become less lamentable when we extend our view from the individual to the race. Indeed, it is much the other way. Men’s wishes are not always vain, nor is every life too brief to satisfy its possessor. Only when we attempt, from the point of view permitted by physics and biology, to sum up the possibilities of collective human endeavour, do we fully realise the “vanity of vanities” proclaimed by the Preacher. I am not, of course, suggesting that history is uninteresting because men are unhappy: nor yet that naturalism carries pessimism in its train. It may well be that if mankind could draw up a hedonistic balance-sheet, the pleasures of mundane existence would turn out to be greater than its sufferings. But this is not the question. I am not (for the moment) concerned with the miseries of the race, but with its futility. Its miseries might be indefinitely diminished, yet leave its futility unchanged. We might live without care and die without pain; nature, tamed to our desires, might pour every luxury into our lap; and, with no material wish unsatisfied, we might contemplate at our ease the inevitable, if distant, extinction of all the life, feeling, thought, and effort whose reality is admitted by a naturalistic creed. But how should we be advanced? What interest would then be left in the story of the human race from its sordid beginnings to its ineffectual end? Poets and thinkers of old dimly pictured a controlling Fate to which even the Olympian gods were subject. The unknown power, which they ignorantly worshipped, any text-book on physics will now declare unto you. But no altars are erected in its honour. Its name is changed. It is no longer called Fate or Destiny, but is known by a title less august if more precise, the law of energy-degradation, or (if you please) “the second law of thermo-dynamics.” It has become the subject of scientific experiment; the physicists have taken it over from the seers, and its attributes are defined in equations. All terrestrial life is in revolt against it; but to it, in the end, must all terrestrial life succumb. Eschatology, the doctrine of the last things, has lapsed from prophecy to calculation, and has become (at least potentially) a quantitative science.