I can’t help you if you don’t want to respect the definition of “theory.” It’s a real word with real meaning, even if you don’t grasp that.

And yes, it is a science. Marxism is economic science. Haven’t you read Capital before, with all this bluster? It’s a study and investigation with metholodogies, citations, and peer reviews.

Try reading it. You might be surprised to learn off you were.