I would say that Math is about understanding the world as well :) And OO is definitely possible without making encapsulating mutation the mantra. If programming in common lisp taught me anything it was that mixing and matching functional and object orient approaches depending on the problem at hand is the overall best approach.
As much as I like lisp there's nothing wrong with some good OO, like the one available in Smalltalk. I kind of wish for a nice mix of the two to emerge. But I have no Idea what that would look like.
I've had colleagues switching to Emacs from vim because of magit so there's that.
http://books.pharo.org/spec-tutorial/ I believe this one is for a previous version of Spec but it might get you going. Classes like ComposablePresenter have been replaced by SpPresenter, everything related to Spec has gotten the Sp-prefix in later pharo versions.