The laughter is one of the important elements in the field of the therapy. The effect of the laughter therapy is proved already on the biological plan as well as on the psychological plan. And then, it is necessary to study the laughter on all the aspects. For the first step, we want to show here the meanings of the laughter on the sociological plan in France in 17th century in the literature of that period. In the XVIIth century the \"laughter\" becomes suspect to the point that it considers as a roguish intention of the people born \"pervert\", and to the point that it harms the social system and its established value. But, although the laughter is not encouraged in this century, a device of strengthened control of the canonical shrinkage, supported by subtle arguments in the speeches engendering prohibitions and prescriptions create a rational laughter which stresses the individualization and the refusal of the irrational. We eventually facilitate the blooming of representation of the laughter on the literary plan. It is the comedy that asks to spread this laughter which reminds the public under the diverse forms: satire, irony etc parody, comic. Molière, free spirit, integrate all the arguments which can be provoked by the laughter. On the parallel plan, the novel offers to the laughter more explorable fields than the theatre which wants to avoid the border imposed by the social agreement. This new genre was much more free than the noble and traditional genre to investigate subversively in a fictitious world. Cyrano and Scarron use the laughter to begin a research of the new knowledge in many domains. Finally the laughter in the \"funny literature\" of the XVIIth century, especially at the free thinkers as Molière, Cyrano and Scarron, works as the means to attack the scaffold of the depreciated system at that time but always retained by the ultra-catholics and the despotic spirits.