 In everything that is to excite a lively convulsive laugh there must be something absurd (in which the understanding, therefore, can find no satisfaction). Laughter is an affection arising from the sudden transformation of a strained expectation into nothing. This transformation, which is certainly not enjoyable to the understanding, yet indirectly gives it very active enjoyment for a moment. Therefore its cause must consist in the influence of the representation upon the body, and the reflex effect of this upon the mind.