nourish himself and to prove resistant to the blandishments of sex, that the attempt to squeeze his behaviour into these three categories began to involve an increasingly obvious and finally intolerable amount of pushing and pulling, as well as so much pretence that he was altogether “in,” {17} when, quite plainly, so large a part of him remained “out,” that the enterprise had to be given up, and it was once more discovered that man escaped and must always escape any complete generalization by science.
A more obvious inference would have been that there was some other instinct which had not been taken into account, some impulse, perhaps, which would have no very evident object as regarded the individual, but would chiefly appear as modifying the other instincts and leading to new combinations in which the primitive instinctive impulse was unrecognizable as such. A mechanism such as this very evidently would produce a series of actions in which uniformity might be very difficult to recognize by direct observation, but in which it would be very obvious if the characters of this unknown “x” were available.