Is anything about that theory specific to any time period? Does any part of it refer to a system of "capitalism"?
Marx, and those following Marx, wrote their works under the banner of "communism". Adam Smith did not write under any banner. He made observations.
> Marx gave capitalism a name to talk about it as a step in the thrust of history, contrasting it with earlier feudalism systems, and to argue that it would inevitably lead to its own destruction while advocating that communism is the logical next step. It wasn't just "anything before communism" even for him.
You're not getting what I'm saying. Marx gave capitalism a name, OK. Did he give it a definition? The whole problem I'm talking about here is that people use the word "capitalism" without having a meaning in mind for it to refer to.
It is probably better to contrast capitalism with socialism though, and classical economics with communist theory. Not all capitalists ascribe to classical economics, just like not all socialists ascribe to communist theory.
Marx gave capitalism a name to talk about it as a step in the thrust of history, contrasting it with earlier feudalism systems, and to argue that it would inevitably lead to its own destruction while advocating that communism is the logical next step. It wasn't just "anything before communism" even for him.
Keynes, Hayek, and Smith all have a common thread on their belief in the market, despite the fact that they would in many cases advocate for very different policies.