This problem is known in the philosophy of science as the underdetermination problem. Multiple hypotheses can fit the data. If we don’t assign a priori probabilties to hypotheses, we will never reach a conclusion.
For example, the hypothesis that (a) Stephen Hawking lived till 2018 against (b) There was a massive conspiracy by his relatives and friends to take his existence after his death in 1985. (That was an actual conspiracy theory). No quantity of evidence can refute the second theory. We can always increase the number of conspirators.
The only reason we choose (1) over (2) is the implausibility of (2).
This problem is known in the philosophy of science as the underdetermination problem. Multiple hypotheses can fit the data. If we don’t assign a priori probabilties to hypotheses, we will never reach a conclusion. For example, the hypothesis that (a) Stephen Hawking lived till 2018 against (b) There was a massive conspiracy by his relatives and friends to take his existence after his death in 1985. (That was an actual conspiracy theory). No quantity of evidence can refute the second theory. We can always increase the number of conspirators. The only reason we choose (1) over (2) is the implausibility of (2).