Page:Popular Science Monthly Volume 15.djvu/695

 countless ages. Each new insight into natural phenomena on the part of man, each act of wiser doing founded on truer insight, each bettered feeling which has been developed from wiser conduct, has tended to determine by degrees a corresponding structural change of the brain, which has been transmitted as an innate endowment to succeeding generations, just as the acquired habit of a parent animal becomes sometimes the instinct of its offspring; and the accumulated results of these slow and minute gains, transmitted by hereditary action, have culminated in the higher cerebral organization, in which they are now, as it were, capitalized. Thus the added structure embodies in itself the superior intellectual and moral capacities of abstract reasoning and moral feeling which have been the slow acquisitions of the ages, and it gives them out again in its functions when it discharges its functions rightly. If we were to have a person born in this country with a brain of no higher development than that of the low savage—destitute, that is, of the higher nervous substrata of thought and feeling—if, in fact, our far remote prehistoric ancestors were to come to life among us now—we should have more or less of an imbecile, who could not compete on equal terms with other persons, but must perish, unless charitably cared for, just as the native Australian perishes when he comes into contact and competition with the white man. The only way in which the native Australian could be raised to the level of civilized feeling and thought would be by cultivation continued through many generations—by a process of evolution similar to that which lies back between our savage ancestors and us.

That is one aspect of the operation of natural law in human events—the operation of the law of heredity in development, in carrying mankind forward, that is, to a higher level of being. It teaches us plainly enough that the highest qualities of mind bear witness to the reign of law in nature as certainly as do the lowest properties of matter, and that if we are to go on progressing in time to come, it must be by observation of, and obedience to, the laws of development. But there is another vastly important aspect of the law of heredity, which it concerns us to bear sincerely in mind—its operation in working out human degeneracy, in carrying mankind downward, that is, to a lower level of being. It is certain that man may degenerate as well as develop; that he has been doing so both as nation and individual ever since we have records of his doings on earth. There is a broad and easy way of dissolution, national, social, or individual, which is the opposite of the steep and narrow way of evolution. Now, what it behooves us to realize distinctly is, that there is not anything more miraculous about the degeneracy and extinction of a nation or of a family than there is about its rise and development; that both are the work of natural law. A nation does not sink into decadence, I presume, so long as it keeps fresh those virtues of character through which it became great among nations; it is when it suffers them to be eaten away