And OOP here means these two things from Kay: (i)'In computer terms, Smalltalk is a recursion on the notion of computer itself. Instead of dividing "computer stuff" into things each less strong than the whole--like data structures, procedures, and functions which are the usual paraphernalia of programming languages--each Smalltalk object is a recursion on the entire possibilities of the computer.'
(ii) "Four techniques used together--persistent state, polymorphism, instantiation, and methods-as-goals for the object--account for much of the power."
i, ii are from http://www.smalltalk.org/smalltalk/TheEarlyHistoryOfSmalltal...