Habits that have endured for many thousands of years are not easy to throw off--least of all when they are habits of thought, and when they do not come into open conflict with changing circumstances, or do not clearly involve us in loss or inconvenience. Yet the loss may be great without our knowing anything about it. Before 1590 no one knew how inconvenient were our natural habits of thought about the ways in which a stone may fall; yet the modern world began when Galileo discovered what really happens. Only persons thought to be crazy knew before 1800 that ordinary traditional ideas as to cleanliness are dangerously inadequate. The infant’s average ‘expectation of life’ has increased by about 30 years since Lister upset them. Nobody before Sir Ronald Ross knew what were the consequences of thinking about malaria in terms of influences and miasmas instead of in terms of mosquitoes. The Roman Empire might perhaps have still been flourishing if someone had found this out before A.D. 100. With such examples all about us we can no longer, in any department of life, so easily accept what was good enough for our fathers as good enough for ourselves, or for our children. We are forced to wonder whether our ideas, even upon subjects apparently of little practical importance, such as poetry, may not be dangerously inadequate. It becomes indeed somewhat alarming to recognize, as we must, that our habits of thought remain, as regards most of our affairs much as they were 5,000 years ago. The Sciences are, of course, simply the exceptions to this rule. Outside the Sciences--and the greater part of our thinking still goes on outside the Sciences--we think very much as our ancestors thought a hundred or two hundred generations ago. Certainly this is so as regards official views about poetry. Is it not possible that these are wrong, as wrong as most ideas of an equally hoary antiquity? Is it not possible that to the men of the future our life to-day will seem a continual, ceaseless disaster due only to our own stupidity, to the nervelessness with which we accept and transmit ideas which do not and never have applied to anything? _The average educated man is growing more conscious_, an extraordinarily significant change. It is probably due to the fact that his life is becoming more complex, more intricate, his desires and needs more varied and more apt to conflict. And as he becomes more conscious he can no longer be content to drift in unreflecting obedience to custom. He is forced to reflect. And if reflection often takes the form of inconclusive worrying, that is no more than might be expected in view of the unparalleled difficulty of the task. To live reasonably is much more difficult to-day than it was in Dr. Johnson’s time, and even then, as Boswell shows, it was difficult enough.