Like many other discussions about objects / OO, some of the confusion comes from having several (often contradictory) definitions of what constitutes an object.

Like many other discussions about objects / OO, some of the confusion comes from having several (often contradictory) definitions of what constitutes an object. Is it an agent that responds to a given set of messages? Is it an instance of a class? What about prototypes? Is inheritance fundamental? What about CLOS? Etc.