The delusion which so many people hold, that it is impossible to put artificial restraint on the relations between the sexes, is amazing. Restraint is already a _fait accompli_. Every civilized nation already puts restrictions on numerous classes of people, as has been noted--minors, criminals, and the insane, for example. Even though this restriction is usually based on legal, rather than biological grounds, it is nevertheless a restriction, and sets a precedent for further restrictions, if any precedent were needed. [Illustration: "MONGOLIAN" DEFICIENCY FIG. 29.--A common type of feeble-mindedness is accompanied by a face called Mongoloid, because of a certain resemblance to that of some of the Mongolian races as will be noted above. The mother at the left and the father were normal. This type seems not to be inherited, but due to some other influence,--Goddard suggests uterine exhaustion from too many frequent pregnancies.] It is, we conclude, both desirable and possible to enforce certain restrictions on marriage and parenthood. What these restrictions may be, and to whom they should be applied, is next to be considered. CHAPTER IX THE DYSGENIC CLASSES Before examining the methods by which society can put into effect some measure of negative or restrictive eugenics, it may be well to decide what classes of the population can properly fall within the scope of such treatment. Strictly speaking, the problem is of course one of individuals rather than classes, but for the sake of convenience it will be treated as one of classes, it being understood that no individual should be put under restriction with eugenic intent merely because he may be supposed to belong to a given class; but that each case must be investigated on its own merits,--and investigated with much more care than has hitherto usually been thought necessary by many of those who have advocated restrictive eugenic measures. The first class demanding attention is that of those feeble-minded whose condition is due to heredity. There is reason to believe that at least two-thirds of the feeble-minded in the United States owe their condition directly to heredity,[80] and will transmit it to a large per cent of their descendants, if they have any. Feeble-minded persons from sound stock, whose arrested development is due to scarlet fever or some similar disease of childhood, or to accident, are of course not of direct concern to eugenists.