No there are ways to establish causation separate from correlation. It's easy. Imagine, you observe someone with his hand on a switch. Every time he flips the

No there are ways to establish causation separate from correlation. It's easy. Imagine, you observe someone with his hand on a switch. Every time he flips the switch the light turns on or off. This is correlative. You observe a correlation between switch flipping and lights going on and off. You can guess that the switch "causes" the light to go on. However correlations do not indicate causation. It could be the switch doesn't do anything. The person is simply observing when the light goes on flipping the switch at the same time. To do a causative experiment you have to become the flip switcher yourself. You have to randomly flip the switch and observe the lights reaction when it is flipped and when it is not flipped. Doing this more and more yourself as the experimenter gives you more and more confidence that the switch is causative to the light going on. Essentially that is what a causative experiment requires. The experimenter must intervene with the subject itself in order to determine causation. Observational experiments are not enough to determine causation. Judea pearl gets into this deeper with counterfactuals which actually imo is more technically correct but makes the whole thing harder to understand. Anyway if you look at clinical trials this is exactly what they do to see if a certain medicine "causes" something. Keep in mind that correlation and causation is sort of separate from the fact that science can't "prove" anything. Correlation is simply a probabilistic number and so is causation. Proof is something outside of this that exists in mathematics and logic.