[ajuc]

According to Alan Key, who invented the term:

> 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. [1]

You can do this easily with multimethods, in fact they allow for significantly "later" binding than traditional OO languages like Java or C++.

[1] http://userpage.fu-berlin.de/~ram/pub/pub_jf47ht81Ht/doc_kay...