One might say, the will of animal creatures is set in motion in two different ways: either by motivation or by instinct; thus from without, or from within; by an external occasion, or by an internal tendency; the former is explicable because it lies before us without, the latter is inexplicable because it is merely internal. But, more closely considered, the contrast between the two is not so sharp, indeed ultimately it runs back into a difference of degree. The motive also only acts under the assumption of an inner tendency, _i.e._, a definite quality of will which is called its _character_. The motive in each case only gives to this a definite direction—individualises it for the concrete case. So also instinct, although a definite tendency of the will, does not act entirely, like a spring, from within; but it also waits for some external circumstance necessarily demanded for its action, which at least determines the time of its manifestation; such is, for the migrating bird, the season of the year; for the bird that builds its nest, the fact of pregnancy and the presence of the material for the nest; for the bee it is, for the beginning of the structure, the basket or the hollow tree, and for the following work many individually appearing circumstances; for the spider, it is a well‐adapted corner; for the caterpillar, the suitable leaf; for egg‐laying insects, the for the most part very specially determined and often rare place, where the hatched larvæ will at once find their nourishment, and so on. It follows from this that in works of mechanical tendency it is primarily the instinct of these animals that is active, yet subordinated also to their intellect. The instinct gives the universal, the rule; the intellect the particular, the application, in that it directs the detail of the execution, in which therefore the work of these animals clearly adapts itself to the circumstances of the existing case. According to all this, the difference between instinct and mere character is to be fixed thus: Instinct is a character which is only set in motion by a _quite specially determined_ motive, and on this account the action that proceeds from it is always exactly of the same kind; while the character which is possessed by every species of animal and every individual man is certainly a permanent and unalterable quality of will, which can yet be set in motion by very different motives, and adapts itself to these; and on account of this the action proceeding from it may, according to its material quality, be very different, but yet will always bear the stamp of the same character, and will therefore express and reveal this; so that for the knowledge of this character the material quality of the action in which it appears is essentially a matter of indifference. Accordingly we might explain instinct as a character which is beyond all measure one‐sided and strictly determined. It follows from