oscillation of the organs, which promotes the restoration of equilibrium and has a favourable influence upon health.

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 by 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; not, indeed, through the representation being objectively an object of gratification (for how could a delusive expectation