This is an oversimplification, and part of the problem I mention.
The "big leap" in Smalltalk was the idea that everything is an object and computation is message-passing, not just classes and instances. That’s not from Simula. Simula was more like an extension of Algol with OO bolted on. Smalltalk was a whole new conceptual model, which is not as simple to explain as Simula/C++/Java-style OOP.
The "big leap" in Smalltalk was the idea that everything is an object and computation is message-passing, not just classes and instances. That’s not from Simula. Simula was more like an extension of Algol with OO bolted on. Smalltalk was a whole new conceptual model, which is not as simple to explain as Simula/C++/Java-style OOP.