If I may be allowed to use the word “habit,” without any implication as to the time or manner in which it took birth, so as to be equivalent to the corrected phrase “habit or disposition,” that is, as some general principle working in a man’s nature to determine how he will act, then an instinct, in the proper sense of the word, is an inherited habit, or in more accurate language, an inherited disposition. But since it is difficult to make sure whether a habit is inherited or is due to infantile training and tradition, I shall ask leave to employ the word “instinct” to cover both cases.