At the worst, this has reduced philosophy to a show of elaborate terminology, a hair-splitting logic, and a fictitious devotion to the mere external forms of comprehensive and minute demonstration. Even at the best, it has tended to produce an overdeveloped attachment to system for its own sake, and an over-pretentious claim to certainty. Bishop Butler declared that probability is the guide of life; but few philosophers have been courageous enough to avow that philosophy can be satisfied with anything that is merely probable. The customs dictated by tradition and desire had claimed finality and immutability. They had claimed to give certain and unvarying laws of conduct. Very early in its history philosophy made pretension to a similar conclusiveness, and something of this temper has clung to classic philosophies ever since. They have insisted that they were more scientific than the sciences--that, indeed, philosophy was necessary because after all the special sciences fail in attaining final and complete truth. There have been a few dissenters who have ventured to assert, as did William James, that "philosophy is vision" and that its chief function is to free men's minds from bias and prejudice and to enlarge their perceptions of the world about them. But in the main philosophy has set up much more ambitious pretensions. To say frankly that philosophy can proffer nothing but hypotheses, and that these hypotheses are of value only as they render men's minds more sensitive to life about them, would seem like a negation of philosophy itself. In the third place, the body of beliefs dictated by desire and imagination and developed under the influence of communal authority into an authoritative tradition, was pervasive and comprehensive. It was, so to speak, omnipresent in all the details of the group life. Its pressure was unremitting and its influence universal. It was then probably inevitable that the rival principle, reflective thought, should aim at a similar universality and comprehensiveness. It would be as inclusive and far-reaching metaphysically as tradition had been socially. Now there was just one way in which this pretension could be accomplished in conjunction with a claim of complete logical system and certainty.