Consequently, it is not his sudden change of attitude that raises a laugh, but rather the involuntary element in this change,—his clumsiness, in fact. Perhaps there was a stone on the road. He should have altered his pace or avoided the obstacle. Instead of that, through lack of elasticity, through absentmindedness and a kind of physical obstinacy, as a result, in fact, of rigidity or of momentum, the muscles continued to perform the same movement when the circumstances of the case called for something else. That is the reason of the man's fall, and also of the people's laughter.
Now, take the case of a person who attends to the petty occupations of his everyday life with mathematical precision. The objects around him, however, have all been tampered with by a mischievous wag, the result being that when he dips his pen into the inkstand he draws it out all covered with mud, when he fancies he is sitting down on a solid chair he finds himself sprawling on the floor, in a word his actions are all topsy-turvy or mere beating the air, while in every case the effect is invariably one of momentum. Habit has given the impulse: what was wanted was to check the
