From an email to Stefan Ram around 2003.You can read more snippets <a href="http://userpage.fu-berlin.de/~ram/pub/pub_jf47ht81Ht/doc_kay_oop_en">here</a> and <a href="http://lists.squeakfoundation.org/pipermail/squeak-dev/1998-October/017019.html">here</a>.

Alan Kay and OOP

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.

— Alan Kay