#theories are the result of good observations. When a theory allows to predict an output value based on given input values reliable, it can be that the theory is true. When there are cases, where a theory is untrue the whole theory is imperfect and therefore false. Clearly a theory can also define, where it can be used and where it can not be used. This specification has to be considered as well. But then the theory is only true, when these limitations are expressed as well. In the end this means it is very easy to proof a theory false, while it is dificult to proof a theory true. This is why factchecking is very effective and works. Since it proofs a story to be false. And once a story is logically falsified, the story could only be true, when the falsification would be false. This means, we should not evaluate a story based on the source but rather based on the facts it is based.