It has already been pointed out how dangerous it would be to breed man for reason—that is, against suggestibility. The idea is a fit companion for the {64} device of breeding against “degeneracy.” The “degenerate”—that is, the mentally unstable—have demonstrated by the mere fact of instability that they possess the quality of sensitiveness to feeling and to experience, for it is this which has prevented them from applying the remedy of rationalization or exclusion when they have met with experience conflicting with herd suggestion. There can be no doubt as to the value to the State of such sensitiveness were it developed in a congruous environment. The “degeneracy,” therefore, which we see developed as a secondary quality in these sensitive minds is no evidence against the degenerate, but an indictment of the disorderly environment which has ruined them, just as the catchword associating insanity and genius tells us nothing about genius but a great deal about the situation into which it has had the misfortune to be born. Sensitiveness to feeling and experience is undoubtedly the necessary antecedent of any high grade of that power of intercommunication which we have seen to be necessary to the satisfactory development of man. Such sensitiveness, however, in society as it now is, inevitably leads merely to mental instability. That such sensitiveness increases with civilization is shown by the close association between civilization and mental instability. There is no lack, therefore, of the mental quality of all others most necessary to the gregarious animal. The pressing problem which in fact faces man in the immediate future is how to readjust the mental environment in such a way that sensitiveness may develop and confer on man the enormous advantages which it holds for him, without being transformed from a blessing into the curse and menace of instability. To the biologist it is quite clear that this can be effected only by an extension of the rational method to the whole field of experience, a {65} process of the greatest difficulty, but one which must be the next great variation in man’s development if that development is to continue to be an evolution.