I am looking for an exact quote from Jean Dieudonné saying more or less that

    there are three kinds of important problems in mathematics: 
    problems of existence, classification and construction.

The quote may be in French or English, I guess I have read it in the forewords of one of his books, but I can't find it now. I also browsed his book "Pour l'honneur de l'esprit humain" without success.

**EDIT:** I am starting to doubt that it is a quote from Dieudonne. It could be from Andre Weil instead...