The great defect of this view is found in its definitions. We exclaim at once: who made the past the measure of the future? and who made social approval the measure of truth? What is there to eclipse the vision of the poet, the inventor, the seer, that he should not see over the heads of his generation, and raise his voice for that which, to all men else, lies behind the veil? The social philosophy of this school can not answer these questions, I think; nor can it meet the appeal we all make to history when we cite the names of Aristotle, Pascal, and Newton, or of any of the men who single-handed and alone have set guide-posts to history, and given to the world large portions of its heritage of truth. What can set limit to the possible variations of fruitful intellectual power? Rare such variations--that is their law: the greater the variation, the more rare! But so is genius; the greater, the more rare. As to the rat with the human hand, he would not be left to starve and decay in his hole; he would be put in alcohol when he died, and kept in a museum! And the lesson which he would teach to the wise biologist would be that here in this rat Nature had shown her genius by discounting in advance the slow processes of evolution! It is, indeed, the force of such considerations as these which have led to many justifications of the positions that the genius is quite out of connection with the social movement of his time. The genius brings his variations to society whether society will or no; and as to harmony between them, that is a matter of outcome rather than of expectation or theory. We are told the genius comes as a brain-variation; and between the physical heredity which produces him and the social heredity which sets the tradition of his time there is no connection.