“A Monad is just a monoid in the category of

endofunctors …”

Ashwin Rao attempts to demystify the above statement

I was asked to do this talk to demystify the statement:

“A monad in X is just a monoid in the category of endofunctors of X, with product × replaced by

composition of endofunctors and unit set by the identity endofunctor”.

A couple of nice, intuitive explanations are provided at:

http://stackoverflow.com/questions/3870088/a-monad-is-just-a-monoid-in-the-category-of-endofunctors-

whats-the-problem

Since these explanations are not complete, I will attempt to provide some rigor and completeness in

the following 3 (dense and terse) slides in (hopefully) 60 minutes or less.

Please combine the Stackoverflow link explanations with my coverage so that you merge intuition with

rigor to understand this well.

Thanks for being patient in dealing with this dry topic.