Stroustrup's starting-point (page 13) is abstract-data-types not a compile-time-hierarchy —

"Consider defining a type 'shape' for use in a graphics system. Assume for the moment that the system has to support circles, triangles, and squares. Assume also that you have some classes … You might define a shape like this … This is a mess. …"

Then —

"The problem is that there is no distinction between the general properties of any shape … and the properties of a specific shape … The ability to express this distinction and take advantage of it defines object-oriented programming. …

The programming paradigm is: Decide which classes you want; provide a full set of operations for each class; make commonality explicit by using inheritance. …

Where there is no such commonality, data abstraction suffices."