Abstract
The world success of the sustainable development concept, become impossible to circumvent, causes certain consequences: for example, the generalized use of the ethical term. From now on, this establishes it as an obliged reference to the detriment of that of morals, too connoted. But this profusion generates confusion and reduction of meanings. We endeavour to distinguish ethics from morals in order to make meanings emerge from this multiplicity of the "ethical" adjective use. This distinction will enable us to question the tour-operators practices and consequently, to question the possibility of evaluating and of controlling the ethical character of a tour-operator. Is one able today to evaluate and control without measuring?