The problem is that naive empiricism is not good enough for most non-trivial practical applications.
(Where a trivial application would be figuring out that a hammer makes a sound when you bash it against a piece of wood, which will virtually always happen assuming certain standard conditions.)
For another example of this failure mode, look at the history of medicine. At least some of the practitioners there were clearly empiricists, otherwise it seems very unlikely that they would have settled on willow bark (which contains salicylic acid). But plenty of other treatments are today recognized as actively harmful. This is because empiricism and good intentions are not enough to do medical statistics successfully.
Look at the replication crisis for another data point: Even being part of a tradition ostensibly based on experimental rigor is not enough to halfway consistently arrive at the truth.
If you are testing the hypothesis “I am a wizard” versus the null hypothesis “I am a muggle”, it is likely that the former is much preferable to the experimenter than the latter. This means that they will be affected by all sorts of cognitive biases (as being an impartial experimenter was not much selected for in the ancestral environment) which they are unlikely to even know (unless they have Read The Sequences or something alike).
If it comes to testing oneself for subtle magic abilities, it would take a knowledgeable and rigorous rationalist to do that correctly. I certainly would not trust myself to do it. (Of course, most rationalists would also be likely to reject the magic hypothesis on priors.)
The problem is that naive empiricism is not good enough for most non-trivial practical applications.
(Where a trivial application would be figuring out that a hammer makes a sound when you bash it against a piece of wood, which will virtually always happen assuming certain standard conditions.)
For another example of this failure mode, look at the history of medicine. At least some of the practitioners there were clearly empiricists, otherwise it seems very unlikely that they would have settled on willow bark (which contains salicylic acid). But plenty of other treatments are today recognized as actively harmful. This is because empiricism and good intentions are not enough to do medical statistics successfully.
Look at the replication crisis for another data point: Even being part of a tradition ostensibly based on experimental rigor is not enough to halfway consistently arrive at the truth.
If you are testing the hypothesis “I am a wizard” versus the null hypothesis “I am a muggle”, it is likely that the former is much preferable to the experimenter than the latter. This means that they will be affected by all sorts of cognitive biases (as being an impartial experimenter was not much selected for in the ancestral environment) which they are unlikely to even know (unless they have Read The Sequences or something alike).
If it comes to testing oneself for subtle magic abilities, it would take a knowledgeable and rigorous rationalist to do that correctly. I certainly would not trust myself to do it. (Of course, most rationalists would also be likely to reject the magic hypothesis on priors.)