Causation and correlation
Causation is the concept that one process has an effect on another process. For example, gravitation causes objects to fall to the ground. People use causation to deduce how nature works. For example, 18th century people explained objects falling to the ground using gravitation. But their explanation was not complete as it didn’t explain how gravitation caused objects to fall. In the 20th century, people explained the same phenomenon using spacetime curvature. But their explanation was not complete as it didn’t explain how objects caused curvature of spacetime. So the explanation for this phenomena remains incomplete in spite of deep understanding. Explanations of causations will always be incomplete. This is because it is impossible for people to perceive all processes that cause an effect. People fill this gap with intuition. Moreover, any explanation of causation will only be a guess as people can’t perceive causation. They can only perceive the effect. For example, people can’t perceive how the earth causes objects to fall, they can only perceive objects falling. So the concept of causation itself is not rational as people have never perceived it. People can rationally only claim that some processes consistently occur together. The rational explanation of relationship of such processes is that they are correlated. Thus the human concept of causation is actually correlation.