[The symbolic payment: desirable money].

Because of the "free" therapy provided in the health and social services network, it is often difficult to make patients realize they ought to invest in their treatment. The authors first introduce the concepts supporting the idea of a "symbolic payment", designed to help solve some of these difficulties. Also, they recount anecdotes resulting from the application of this approach in clinics. In conclusion, the authors point to avenues that could lead to a broadening of the concepts underlying this clinical tool.