In its most general form, the thesis of this chapter can be succinctly put: we have brought to the writing of the history of methodology certain preconceptions which jointly render it almost impossible to understand the evolution of this subject. These preconceptions concern both the nature of philosophy and the aims of history. Until those conceptions are altered, I venture to claim, the history of methodology will not deserve the serious attention which it would otherwise warrant. I want to talk about this family of related philosophico-historical conceptions, using some specific examples to indicate the problem and to underscore its acuteness.