1 6 THE AMERICAN JOURNAL OF SOCIOLOGY
sociology, and who cannot lay any claim whatever to be biologists, ought to keep silence. We have this afternoon had extremely divergent views put before us as to the actual and probable operation of heredity, and it seems quite clear that before we begin to tackle this question, which deals with one of the most powerful of human passions, with a view to regulate it, we must have highly perfected knowledge. We must have the chart properly mapped out before we do anything that might lead us into greater danger than we at present incur.
As to the two factors, stock and environment, no one can doubt that both are of fundamental importance in relation to the welfare of society ; and no one can doubt that, if the kind of precise knowledge which I desiderate could be laid before us by the biologist, it would have considerable influence on our views of what is not only ethically right, but what could be legislatively enforced. Of these two factors, stock and environment, which can we modify with the greater ease and certainty of not doing harm ? It is fairly obvious that we can affect the environment of mankind in certain definite ways. We have the accumulation of considerable tradition as to the way a given act will affect the social environment. When we come to bring stock into consideration, we are still dealing with that which is very largely unknown. At the same time, we owe a great deal of thanks to Mr. Galton for raising this subject. On the one hand, it seems to me that the bare conception of a conscious selection as a way in which educated society would deal with stock is infinitely higher than natural selection with which biologists have confronted every proposal of sociology. If we are to take the problem of stock into consideration at all, it ought to be in the way of intelligently handling the blind forces of nature. But until we have far more knowledge and agreement as to criteria of conscious selection, I fear we cannot, as sociologists, expect to do much for our society on these lines.
BY G. A. ARCHDALL REID, M.D.
I think it would be impossible to imagine a subject of greater importance, or to name one of which the public is more ignorant. At the root of every moral and social question lies the problem of heredity. Until a knowledge of the laws of heredity is more widely diffused, the public will grope in the dark in its endeavors to solve many pressing difficulties.
How shall we bring about a " wide dissemination of a knowledge of the laws of heredity, so far as they are surely known, and the promotion of their further study " ? We shall not be able to reach the public until we are able to influence the education of a body of men whose studies naturally bring them into relation with the subject, and who, when united, are numerous enough and powerful enough to sway public opinion. Only one such body of men exists the medical profession. When the study of heredity forms as regular a part of the medical curriculum as anatomy and physiology, then, and not till then, will the laws of heredity be brought to bear on the solution of social problems. At present a specialist like Mr. Galton has a very limited audience. In effect, it is com- posed of specialists like himself. Until among medical men a systematic knowl- edge of heredity is substituted for a bundle of prejudices, and close and clear reasoning for wild guesswork, the influence of men of Mr. Galton's type most unhappily is not likely to extend much beyond the limits of a few learned societies.
The first essential is a clear grasp of the distinction which exists between what are known as inborn traits and what are known as acquired traits. Inborn traits are those with which the individual is " born," which come to him by nature, which form his natural inheritance from his parents. Acquired traits are alterations produced in inborn traits by influences to which they are exposed during the life of the individual. Thus a man's limbs are inborn traits, but the changes produced in his limbs by exercise, injury, and so forth are acquired traits. All men know that the individual tends to transmit his inborn traits to his offspring. But it is now almost universally denied by students of heredity that he tends to transmit his acquired traits. The real, the burning question among students of heredity is whether changes in an individual caused by the
