This idea was held almost without question by the biologists of the
past, from Aristotle on. Questionings indeed arose from time to time,
but they were vague and carried no weight, until a generation ago
several able men elaborated them. For many years, it was the question of
chief dispute in the study of heredity. The last word has not yet been
said on it. It has theoretical bearings of immense importance; for our
conception of the process of evolution will be shaped according to the
belief that acquired characters are or are not inherited. Herbert
Spencer went so far as to say, "Close contemplation of the facts
impresses me more strongly than ever with two alternatives--either that
there has been inheritance of acquired characters, or there has been no
evolution." But its practical bearings are no less momentous. Again to
quote Spencer: "Considering the width and depth of the effects which the
acceptance or non-acceptance of one or the other of these hypotheses
must have on our views of life, the question, Which of them is true?
demands beyond all other questions whatever the attention of scientific
men. A grave responsibility rests on biologists in respect of the
general question, since wrong answers lead, among other effects, to
wrong belief about social affairs and to disastrous social actions."

Biologists certainly have not shirked this "grave responsibility" during
the last 30 years, and they have, in our opinion, satisfactorily
answered the general question. The answer they give is not the answer
Herbert Spencer gave.

But the popular mind frequently lags a generation behind, in its grasp
of the work of science, and it must be said that in this case the
popular mind is still largely under the influence of Herbert Spencer and
his school. _Whether they know it or not_, most people who have not made
a particular study of the question still tacitly assume that the
acquirements of one generation form part of the inborn heritage of the
next, and the present social and educational systems are founded in
large part on this false foundation. Most philanthropy starts out
unquestioningly with the assumption that by modifying the individual for
the better, it will thereby improve the germinal quality of the race.
Even a self-styled eugenist asks, "Can prospective parents who have
thoroughly and systematically disciplined themselves, physically,
mentally and morally, transmit to their offspring the traits or
tendencies whi