In spite of all the syntactical, lexical, grammatical, discursive or even pragmatic limitations ESP represents and which will not be examined here, we would like to show how much ESP is a field of freedom. First, a field of freedom for the students, future technicians, engineers or scientists, who receive, at the same time as they receive that English, an unavoidable and indispensable tool both ... [Show full abstract] in their learning and in their future jobs. It is a tool for their professional freedom, and a guarantee, in the secure knowledge they must have of it, that they will not cause any light or serious incident or accident. For the teacher, ESP is also a field of freedom. First because class-syllabi are worthless. Then, because text-books are non-existent or very light in the field of industrial ESP we are here concerned with. Finally because an ESP pedagogy does not exist and remains to be devised on the basis of an exact description of this ESP and not of some British, more or less literary, rather old type of English. It is the teacher’s responsibility and both pedagogical and didactic freedom: he must do everything all by himself.