> Actually objects in the early Lisp were simply symbols with their property lists.
I was quite surprised to see that this already existed, together with the "property" terminology, in McCarthy's primordial "pre-LISP" list processing system described in AN ALGEBRAIC LANGUAGE FOR THE MANIPULATION OF SYMBOLIC EXPRESSIONS. Basically any time we say that an object has properties, we are referring to that.
I was quite surprised to see that this already existed, together with the "property" terminology, in McCarthy's primordial "pre-LISP" list processing system described in AN ALGEBRAIC LANGUAGE FOR THE MANIPULATION OF SYMBOLIC EXPRESSIONS. Basically any time we say that an object has properties, we are referring to that.