> OOP to me means only messaging, local retention and protection and hiding of state-process, and extreme late-binding of all things. It can be done in Smalltalk and in LISP. There are possibly other systems in which this is possible, but I'm not aware of them.

This seems to be Kay's key point. The description of object orientation is very unlike any modern system I've used, and he mentions elsewhere that even modern Smalltalks fail to live up to it.

My problem with this vision of OOP is that it would seem to take a great deal more support from the programming environment to make it work, compared to FP. Or perhaps the problem is that this "true" OOP is so much harder to grasp that it's impossible for me to approximate it in another language, where with FP I can obtain some of the benefits just by writing pure functions in an otherwise imperative language.