ME TIT EOM: OF ExmatExer. Most of the modern critics of natural selection eontend that the raw material of which it is said to stand in need is supplied by that influence of the condi tions of life which we are accustomed to slim up 'under the general word 'experience.' Fhey attribute to individual or to ancestral experi ence the origin of the adaptive actions which natural selection picks out and preserves. Our own times, like the two preceding centuries, are notable for the prevalence of 'experience phi losophy': vet. there has been little reflective or philosophical study of experience in the light of modern biology, although it is dear that the biologist who asserts that experience furnishes the raw material which natural selection picks out and preserves must he preivired to give an account of experience which does not attribute it to natural flecent experiments show that when an animal is placed in such circumstances that it C.111, by some simple action which is well within the com mand of its organization, obtain some object that it likes, the way in which it acquires facil ity in accomplishing the desired action is very noteworthy. and strikingly the same in all the animals that have been studied. A monkey, for example, before Which is placed a box that contains, in full but out of reach, some at traetive article of food. which can be obtained only by some simple hut defi nite action, such as pulling a string, or lifting a latch, or pulling out a peg, shows no capa city for learning to perform this action through seeing it done, or by being shown NV to lb) it. If, however, any one among the indefinite and uncoordinated and aimless movements which it makes in trying to reach the object happens to be the proper one and to succeed, and if the time which has been consumed in irrelevant movements he noted, it is found that the adap tive movement comes a little sooner at the sec ond trial. and that, as the experiment is repeat ed day after day. the interval between the be ginning of effort and success grows shorter and shorter, until at last, in course of time, the monkey 'acquires' the art of lifting the latch or of pulling the string without any preceding misdirected movements. Ho has 'learned by experience' to perform the responsive action tin der the stimulus of its sensible perception, and thus to gain the desired end: but his experience has come about through the gradual extinction of the aimless and misdirected movements. and the survival of those that are definite and exact. Experiments with fishes and turtles and other animals give the same result. They learn by experience, hut their experience consists in the survival of the fittest activities and the inhibi tion of those that are unsuccessful.
The eyes of the human infant move independ ently and aimlessly, and it is only after it has spent weeks in experimenting that it suppresses the vague and indefinite movements, and thus gradually and slowly acquires the useful art of coordinating compensating muscles in such a way as to move both eves together so as to see ob jects single and solid, instead of that and tremu lous.
Herbert Spencer has pointed out the way in which opinion as to the limits and scope of the powers of governments over the governed has undergone slow modification with the progress of civilization until most of the extraneous and irrelevant notions of earlier and more primitive peoples have been stripped off, leaving only that which is essential to survive and come down to modern times.
"All science," says Huxley, "starts with hy potheses—in other words, with assumptions that are unproved,. while they may be. and often are. erroneous: but which are better than nothing to the seeker after order in the maze of phe nomena. And the historical progress of every science depends upon the critic-ism of hypotheses —on the gradual stripping off, that is, of their untrue or superficial parts—until there remains only that exact verbal expression of as much as we kilo NV of the fact, and no more, which con stitutes a perfect scientific theory." It surely requires only a comprehensive view of these examples of 'experience,' drawn from the most widely separated types of vital activity, to see that they all consist in the extinction of the aberrant and the misdirected and the unco ordinated, until only that which is exact and definite survives. There is, therefore, much to urge in defense of Berkeley's contention that ''the work of experience is to unravel our preju dices and mistakes. untwisting the closest con nections, distinguishing things that are different, instead of and perplexed. giving his distinct views, gradually correcting our judg ment and reducing it to a philosophical exact ness." But the correction of vital activities, and their reduction to exactness by the extinc tion of those that arc confused and perplexed, and the survival of those that are definite and distinct, is what we mean by natural selection.
If _Berkeley is right, if our own experience is but conscious recognition of the universal prev alence and unceasing continuity of the selective process. what becomes of the nation that experi ence is an activity precedent to selection, and the source of the fitness which it picks out and preserves? In a word, what becomes of the 'phi losophy of experience' which meets with so much approvril from many modern men of science?