Oh, correlation does point to causality. What you don't immediately know is where to put the causal arrows. A and B occur together with a high probability: does A cause B, or B cause A? Or do they have a common cause?
Mere statistics cannot do that detective work for us, I'm afraid. But when a pure cause-and-effect relationship is uncovered and reproduced, the correlation will be 100%: remove the cause, the effect disappears. Restore the cause, and the effect appears reliably.
For instance, if we stop the flow of electric current through a coil, the magnetic field will collapse soon afterward. If we start the current again, the field comes back. Moreover, if we place a coil into a similar magnetic field, that field doesn't produce current. These things are 100% reproducible. It's not some weak statistic like "in coils where current was present, the magnetic field was observed to be 3.5% stronger on average". That kind of situation shows that some effects which are not being controlled for are masking the underlying causes and effects.
Exactly, correlation does "point to" causality. The question is what "establishes" it.
Also, agreed, use of controlled experiments is probably the best we can do to validate the hypothesis, and then assume its correctness beyond doubt till counter examples show up, if at all.
Correlation does not need to be 100% though. We live in the world of quantum mechanics today where you can successfully predict the probability distribution, but not beyond (at least as yet).
Mere statistics cannot do that detective work for us, I'm afraid. But when a pure cause-and-effect relationship is uncovered and reproduced, the correlation will be 100%: remove the cause, the effect disappears. Restore the cause, and the effect appears reliably.
For instance, if we stop the flow of electric current through a coil, the magnetic field will collapse soon afterward. If we start the current again, the field comes back. Moreover, if we place a coil into a similar magnetic field, that field doesn't produce current. These things are 100% reproducible. It's not some weak statistic like "in coils where current was present, the magnetic field was observed to be 3.5% stronger on average". That kind of situation shows that some effects which are not being controlled for are masking the underlying causes and effects.