It is not merely the brevity by which the haiku isolates a particular group of phenomena from all the rest; nor its suggestiveness, through which it reveals a whole world of experience. It is not only in its remarkable use of the season word, by which it gives us a feeling of a quarter of the year; nor its faint all-pervading humour. Its peculiar quality is its self-effacing, self-annihilative nature, by which it enables us, more than any other form of literature, to grasp the thing-in-itself.