Nor can either quality be defined in other than psychological terms. The critical sense is rooted in the instincts of attraction and repulsion, the reaction of an organism to any new stimulus being _pro_ or _con_ according to the preëstablished harmony or antagonism between them. As each human being grows to maturity by responding to experience, he acquires his individual set of opinions and ideals, largely borrowed from the habits and conventions of his groups, ethnic, social, and what not, with a small residue of his own originality. Equipped with this outfit of criteria he looks upon life and finds it complete or wanting, tests his fellow men and approves or condemns, examines all created things and calls them good or bad. But he is so constituted that his acquiescence is likely to be somewhat passive, and his protests active, his commendation grudging and qualified, his condemmation sweeping and thorough. Says an eighteenth century satirist,--[1] “Broad is the road, nor difficult to find, Which to the house of Satire leads mankind; Narrow and unfrequented are the ways, Scarce found out in an age, which lead to praise.” The humorous sense is likewise an essence and an index of disposition. The inadequacy of most definitions of the ludicrous, from Aristotle’s “innocuous, unexpected incongruity,” to Bergson’s “mechanical inelasticity,” lies in their concentration on the objective side of it,--the stimulus to mirth,--whereas the subjective,--the mirthful person,--deserves the emphasis. Laughter throws a far more illuminating ray on the laugher than the laughed at, for it indicates not only taste and mood but the trend of one’s philosophy. In betraying a man’s idea of the incongruous, it implies his conception of the congruous, and reveals his whole coördination of life. We may, it is true, define humor by saying that intellectually it is a contemplation of life from the angle of amusement, and emotionally, a joyous effervescence over the absurdities in life ever present to the discerning eye; but we can never quite capture it, any more than pleasure or tragedy. We can, however, use these abstractions as refracted definers of character, by noting what sort of a man it is who regards such and such things as amusing, or delightful, or unendurable. For not only as a man thinks, but also as he laughs and exults and censures and suffers, so is he. That satire is woven from double strands, the blue of rebuke and the red of wit,--becoming thereby in a chromatic sense the purple patch of literature,--is testified to by satiric theory as well as practice. The critical element may of course be taken for granted, but since it has been sometimes over-emphasized at the expense of the humorous, some testimony as to the latter must be given.