To be fair, I don't know a single person that explains things using > "just a monoid in the category of endofunctors" In fact, even among people who DO know t

To be fair, I don't know a single person that explains things using > "just a monoid in the category of endofunctors" In fact, even among people who DO know the category theory necessary to understand this expression it's considered a very obtuse and useless explanation. Especially in the context of Haskell. As for good readable introductions, I consider Wadler's paper "Monads for Functional Programming" to actually be a pretty good introduction. Another good intro is "You Could Have Invented Monads! (And Maybe You Already Have.)" http://blog.sigfpe.com/2006/08/you-could-have-invented-monads-and.html http://blog.sigfpe.com/2006/08/you-could-have-invented-monad...