There's also a written conversation you can find online where he disqualifies pretty much all of the mainstream languages of being OO.

A lot of people, like you, say that OO == ADTs. Or rather, what ever Simula, C++ and Java are doing. Some will say that inheritance is an integral part of it, other's say it's all about interfaces.

But then there's people who say that Scheme and JavaScript are more object oriented than Java and C#. Or that when we're using channels or actors we're now _really_ doing OOP.

There's people who talk about patterns, SOLID, clean code and all sorts of things that you should be adhering to when structuring OO code.

Then there's people who say that OO is all about the mental model of the user and their ability to understand your program in terms of operational semantics. They should be able to understand it to a degree that they can manipulate and extend it themselves.

It's all very confusing.