> Most programmers I know haven't grasped how to use a system of message passing objects to make the semantics of the underlying language programmable at runtim

> Most programmers I know haven't grasped how to use a system of message passing objects to make the semantics of the underlying language programmable at runtime. Can you please elaborate on this? By “message passing” are you referring to ObjectiveC-style virtual calls - or to message-passing in the context of OOP loose-coupling for disseminating events (i.e. broadcasting) instead of using strong references to call event-handlers?