Usually commonality will be expressed in the members of the superclass.

Even when a superclass method is appropriate for a subclass, that subclass often needs a customized version of the method.

Objects of all classes that extend a common superclass can be treated as objects of that superclass.

The subclass can redefine the superclass method with an appropriate implementation.

A subclass is not allowed to inherit methods that it does not need or should not have.