There are some general differences noted by both layman and psychologist, which, though not subject to quantitative determination, yet seem to differentiate somewhat definitely between feminine and masculine mental activity. These may be set down in general as occurring in the field of emotional susceptibility. Thorndike traces them back to the varying intensity of two human traits earlier discussed: the fighting instinct, relatively much stronger in the male, and the nursing or mothering instinct, much stronger in the female. With this fact are associated important differences in the conduct of men and women in social relations. The maternal instinct is held by some writers, for instance, to be in large measure the basis of altruism, and is closely associated with sensitivity to the needs and desires of others. Thorndike writes: It has been common to talk of women's dependence. This is, I am sure, only an awkward name for less resentment at mastery. The actual nursing of the young seems likewise to involve equally unreasoning tendencies to pet, coddle, and "do for" others. The existence of these two instincts has been long recognized by literature and common knowledge, but their importance in causing differences in the general activities of the two sexes has not. The fighting instinct is in fact the cause of a very large amount of the world's intellectual endeavor. The financier does not think merely for money, nor the scientist for truth, nor the theologian to save souls. Their intellectual efforts are aimed in great measure to outdo the other man, to subdue nature, to conquer assent. The maternal instinct in its turn is the chief source of woman's superiorities in the moral life. The virtues in which she excels are not so much due to either any general moral superiority or any set of special moral talents as to her original impulses to relieve, comfort, and console.[1] [Footnote 1: Thorndike: _loc. cit._, pp. 48-49.] Ordinary observation reveals, as literature has in general recorded, what Havelock Ellis has called the "greater affectability of the female mind." There is evidenced in many women a singular and immediate responsiveness to other people's emotions, a quick intuition, a precise though non-logical discrimination, which, though shared to some extent by all individuals gifted with sympathy and affection, is a peculiarly feminine quality. Indeed when a man possesses it, it is common to speak of him as possessing "almost a woman's intuition." Such emotional susceptibility is manifested in the higher frequency of emotional instability and emotional outbreaks among women than among men, and the decreased power of inhibition which women have over instinctive and emotional reactions. Further than this, women more than men may be said to qualify their judgments of persons and situations by their emotional reactions to them.