John Cottingham  

The philosopher John Cottingham has noted how rationalism, a methodology, became socially conflated with atheism, a worldview:

"In the past, particularly in the 17th and 18th centuries, the term 'rationalist' was often used to refer to free thinkers of an anti-clerical and anti-religious outlook, and for a time the word acquired a distinctly pejorative force (thus in 1670 Sanderson [Preface to Ussher's Power of Princes, 1670] spoke disparagingly of 'a mere rationalist, that is to say in plain English an atheist of the late edition...'). The use of the label 'rationalist' to characterize a world outlook which has no place for the supernatural is becoming less popular today; terms like 'humanist' or 'materialist' seem largely to have taken its place. But the old usage still survives."