On the occasion of the celebration of "Twenty Years of Didactique of Ma-
ematics" in France, Jeremy Kilpatrick commented that though the works of
Guy Brousseau are known through texts referring to them or mentioning
their existence, the original texts are unknown, or known only with
difficulty, in the non-Fren- speaking world. With very few exceptions,
what has been available until now have been interpretations of the works
of Brousseau rather than the works themselves. It was in response to
this need that two of us, in the euphoria of an unforgettable Mexican
evening at the time of the 1990 PME conference, decided to undertake the
task of translating into English most of the works of Guy Brousseau. The
ceuvre is immense, and once past the initial moments ofenthusiasm, with
the accompanying ambition to produce the entire of it, we recognized the
need to choose both the texts and a method of proceeding. As far as the
texts go, we chose to take the period from 1970 to 1990, in the course
of which it seemed to us that Brousseau had forged the essentials of the
Theory of Didactical Situations. But even there the collection is huge.
So, after an initial translation of most of the publications of the
period, we carved out a selection, retaining the texts which gave the
best presentation of the principles and key concepts of the Theory.