A monad is just a monoid in the category of endofunctors, what's the problem?
Who first said the following? A monad is just a monoid in the category of endofunctors, what's the problem? And on a less important note, is this true and if so could you give an explanation (hopefully one that can be understood by someone who doesn't have much Haskell experience)? Tom Crockett That particular phrasing is by James Iry, from his highly entertaining Brief, Incomplete and Mostly Wrong History of Programming Languages , in which he fictionally attributes it to Philip Wadler. The original quote is from Saunders Mac Lane in Categories for the Working Mathematician , one of the