Definition of "Object Oriented"

William Cook made an attempt at defining what "Object Oriented" means.

Here's the core of the definition (from

Note the things that are not part of the definition:

From what I can tell, the definition seems accurate to me, but it's also quite technical.

You could certainly use this definition to judge whether a programming language qualifies as object oriented. I wonder whether a similar definition could be found to judge whether a program qualifies as object oriented. (This seems quite a bit harder to me, but would maybe be more useful as a guideline for practitioners.)