I am SO tired of this trope. It may indeed be the case that we can't justify a priori via philosophical lucubrations that we arrive at the truth about nature only by using the methods of science. My answer to that is increasingly becoming, "So bloody what?” The use of science is justified because it works, not because we can justify it philosophically. If we are interested in finding out what causes malaria, no amount of appeal to a deity, philosophical rumination, listening to music, reading novels, or waiting for a revelation will answer that question. We have to use scientific methods, which, of course, is how causes of disease are found.