Those educators who viewed mathematics as vital in the training of logical thinking saw Thorndike’s research
with Woodworth on transfer of training as a shot to the heart of their subject. Transfer of training was the psychological mechanism supporting the theory of mental discipline: the ancient idea the thinking can be trained in general through instruction in specific subjects. Mental discipline is allied both to formal discipline (the view that the form- for example, difficulty, abstraction- of a subject is more important than its content) and to faculty psychology ( the view of the mind as a set of specific faculties requiring exercise for their development).