Where do our ideas come from? Some come from ourselves, or so we think, but most of them are communicated to us by others, and we pass them on in turn. The old philosophical question of the origin of our representations involves analyzing their mode of propagation. In search of the natural origin of culture, Dan Sperber proposes in this book an epidemiology of representations, which describes how ideas reproduce themselves by being transmitted from one individual to another and how, in this process, they undergo transformations akin to mutations. Dan Sperber is an anthropologist and a research director at the CNRS.