_Can we now say how man compares, in the matter of instinct, with the lower animals?_ James commits himself so far as to declare that “no other mammal, not even the monkey, shows so large an array.” The statement is probably true, if we mean by instinct, not a fixed and unchanging mode of response to the given stimulus or situation, but rather an equipment of innate tendencies that may form the basis of all sorts of response; an all-round readiness of behaviour, as it were, such that no stimulus or situation finds us wholly unprepared, while yet the preparation is not so narrow and definite as to force us into special and invariable response. Civilised man ‘reasons’ always on the basis of his instinctive tendencies; his ‘instincts,’ on the other hand, are in general less absorbingly possessive and less close-knit than those of lower forms of life. § 47. =The Two Sides of Instinct.=—If instinct is the general name for the innate nervous tendencies to behaviour, then the detailed study of instinct belongs to physiology and general biology. The psychologist is concerned with it only in so far as the innate tendencies guide and form the stream of thought. There is, however, another side to instinct, which makes it a matter of direct psychological observation; the touching-off of an instinctive response may be accompanied by mental processes, by sensations and feeling. We must say something of instinct in both relations; and we look at it, first, from the =biological= point of view.