By Ralph Johnson, quoted in The Myths of Object-Orientation p.624:
I explain three views of OO programming. The Scandinavian view is that an OO system is one whose creators realise that programming is modelling. The mystical view is that an OO system is one that is built out of objects that communicate by sending messages to each other, and computation is the messages flying from object to object. The software engineering view is that an OO system is one that supports data abstrac- tion, polymorphism by late-binding of function calls, and inheritance.
It seems that in (French) schools we learn the engineering view. Then with experience we can agree on the mystical view. With Smalltalk I think I now understand the Scandinavian view.
Oscar Nierstrasz have written in Ten Things I Hate About OOP:
For me the point of OOP is that it isn’t a paradigm like procedural, logic or functional programming. Instead, OOP says “for every problem you should design your own paradigm”. In other words, the OO paradigm really is: Programming is Modeling