Polymorphism and inheritance were also a big deal for Java and C++, which namespaces don’t provide. That and classes are a way to extend the type system. Kay m

Polymorphism and inheritance were also a big deal for Java and C++, which namespaces don’t provide. That and classes are a way to extend the type system. Kay may not have had those things as his primary conception of OOP, but Smalltalk fully supports inheritance, polymorphism and type extension.