The aim of science is to falsify theories and to replace them by better theories, theories that demonstrate a greater ability to withstand tests. - Alan Chalmers

It should be no news to anyone that the perceptual judgements of individuals can be unreliable for a range of reasons. The challenge, in science, is to arrange the observable situation in such a way that the reliance on such judgements is minimised if not eliminated.

Many kinds of processes are at work in the world around us, and they are all superimposed on, and interact with, each other in complicated ways.

No matter which comes first, the facts or the theory, the question to be addressed is the extent to which the theory is borne out by the facts. The strongest possible claim would be that the theory can be logically derived from the facts. That is, given the facts, the theory can be proven as a consequence of them. This strong claim cannot be substantiated.