Q&A: The Principle of Causality, Quantum Theory, and Popper
The Principle of Causality, Quantum Theory, and Popper
Question
Good evening!
Why don’t we discard the a priori principle that there is causality? After all, in quantum physics it seemingly appears that there is no causality, and according to Popper one should discard a theory that has been falsified (and even not only according to Popper—in this case we are dealing with a strong refutation of the a priori principle itself).
Doesn’t this prove that theories for interpreting reality are chosen on the basis of pragmatism?
Thank you very much!
Answer
First, even in quantum theory there may be causality—hidden variables. In the accepted interpretation, there is indeed no cause in the usual sense. But there is a cause, namely the quantum character of the universe. That itself is the cause of what happens. Things do not just happen for no reason. Beyond that, despite quantum theory, in every other context where we have no different information, we still assume causality. That is true in science and in every other field. So it is quite clear that the accepted assumption is that the principle remains valid even after quantum theory.