For centuries mathematics had had a secure place in the school curriculum as one of the liberal arts. Further, it had by the end of the 16th century become the foundation for mechanics and hence for the ensuing revolutions in science and technology (Keller, 1985). But by the end of the 19th century, it was competing for space in the secondary and collegiate curriculum with newer subjects such as history, the natural sciences, and modern foreign languages. Members of the fledgling field of mathematics education were arguing, in the face of claims that mathematics was not used much in everyday life, for the disciplinary value of their subject. For example, Jacob William Albert Young (1906/1925), of the University of Chicago, contended that still more important than the subject matter of mathematics is the fact that it exemplifies most typically, clearly and simply certain modes of thought which are of the utmost importance to everyone” (p. 17). Mathematicians, too, assumed that the study of mathematics had generative power: "The principal aim of mathematical education is to develop certain faculties of the mind" (Poincare, 1952, p. 128). The argument that what one learns in the study of Mathematics does not transfer to other domains engendered both a reconsideration of the justifications for teaching mathematics and an outpouring of research on transfer.