But needless to insist, the generality and the organization are restricted and fallible. They hold, as Aristotle was fond of pointing out, usually, in most cases, as a rule, but not universally, of necessity, or as a principle. The physician is bound to make mistakes, because individual cases are bound to vary unaccountably: such is their very nature. The difficulty does not arise in _a_ defective experience which is capable of remedy in some better experience. Experience itself, as such, is defective, and hence default is inevitable and irremediable. The only universality and certainty is in a region above experience, that of the rational and conceptual. As the particular was a stepping-stone to image and habit, so the latter may become a stepping-stone to conceptions and principles. But the latter leave experience behind, untouched; they do not react to rectify it. Such is the notion which still lingers in the contrast of "empirical" and "rational" as when we say that a certain architect or physician is empirical, not scientific in his procedures. But the difference between the classic and the modern notion of experience is revealed in the fact that such a statement is now a charge, a disparaging accusation, brought against _a_ particular architect or physician. With Plato, Aristotle and the Scholastic, it was a charge against the callings, since they were modes of experience. It was an indictment of all practical action in contrast with conceptual contemplation. The modern philosopher who has professed himself an empiricist has usually had a critical purpose in mind. Like Bacon, Locke, Condillac and Helvetius, he stood face to face with a body of beliefs and a set of institutions in which he profoundly disbelieved. His problem was the problem of attack upon so much dead weight carried uselessly by humanity, crushing and distorting it. His readiest way of undermining and disintegrating was by appealing to experience as a final test and criterion. In every case, active reformers were "empiricists" in the philosophical sense. They made it their business to show that some current belief or institution that claimed the sanction of innate ideas or necessary conceptions, or an origin in an authoritative revelation of reason, had in fact proceeded from a lowly origin in experience, and had been confirmed by accident, by class interest or by biased authority.