 As we have seen, Mill believes that we can have no genuine knowledge a priori. One important result of this general claim, Mill holds, is that knowledge—on political and ethical matters, as well as within the physical sciences—is more difficult to acquire than those who appeal directly to intuition or common sense might wish. An individual’s need for knowledge far outstrips the possibility of individual observation—as such, the vast majority of our knowledge must be acquired on the basis of testimony.