ABSTRACT
The act of laughter is a type of behaviour, the manifest bodily expression of an emotion, whose private, conscious component is a feeling. Laughter as a challenge for science may be apprehended in two stages: the general challenge of emotions as objects of study for the natural sciences; and within the category of emotions, the special challenge of laughter. The evolutionary history of tickle, physical play, and laughter are intertwined, with tickle and play predating laughter. Concerning life and the mind, there is a 'fundamentalist' attitude, widespread among scientists, that holds firstly that the only valid knowledge is science, and secondly that science means the reduction of a phenomenon to the properties of its material elements. Laughter preceded speech, but then evolved to become a major punctuating element and control tool of verbal communication. God laughs at the creatures who deplore the effects when they continue to cherish the causes'.
