https://bartoszmilewski.com/2016/12/27/monads-categorically/ https://bartoszmilewski.com/2016/12/27/monads-categorically/ This is a book chapter, and you need

https://bartoszmilewski.com/2016/12/27/monads-categorically/ https://bartoszmilewski.com/2016/12/27/monads-categorically/ This is a book chapter, and you need the preceding chapters to grasp it I think. I'm still in the middle of it.