The Greeks had no knowledge of the printing-press, and no literary reviews. They usually took their wisdom out into the market-place, and applied all their efforts to persuade people to acknowledge its value. And it is hard to maintain that wisdom, which is constantly being offered to people, should not adapt itself to people's tastes. It is truer to say that wisdom became accustomed to value itself to the exact degree to which it could count on people's appreciation. In other words, it appears that the value of wisdom, like that of all other commodities, not only with us, but with the Greeks before us, is a social affair. The most modern philosophy has given up concealing the fact. The teleology of the rationalists, who follow Fichte, as well as of the pragmatists who consider themselves the successors of Mill is openly based upon the social point of view, and speaks of collective creations. Truth which is not good for all, and always, in the home market and the foreign--is not truth. Perhaps its value is even defined by the quantity of labour spent upon it. Marx might triumph: under different flags his theory has found admission into every sphere of contemporary thought. There would hardly be found one philosopher who would apply the method of verifying truth which I have proposed; and hardly a single modern idea which would stand the test. _Doctrines and Deductions_ If you want to ruin a new idea--try to give it the widest possible publicity. Men will begin to reflect upon it, to try it by their daily needs, to interpret it, to make deductions from it, in a word to squeeze it into their own prepared logical apparatus; or, more likely, they will cover it up with the _débris_ of their own habitual and intelligible ideas, and it will become as dead as everything that is begotten by logic. Perhaps this explains the tendency of philosophers to so clothe their thoughts that their form may hinder the approach of the general public to them. The majority of philosophic systems are chaotically and obscurely expounded, so that not every educated person can understand them. It is a pity to kill one's own child, and every one does his best to save it from premature death. The most dangerous enemies of an idea are 'deductions' from it, as though they followed of themselves. The idea does not presuppose them; they are usually pressed upon it. Indeed, people very often say: 'The idea is quite right, but it leads to conclusions which are not at all acceptable.' Again, how often has a philosopher to attend the sad spectacle of his pupil's deserting all his ideas, and feeding only upon the conclusions from them. Every thinker who has had the misfortune to attract attention while he was yet alive, knows by bitter experience what 'deductions' are. And yet you will rarely find a philosopher to offer open and courageous resistance to his continuators; and still more rarely a philosopher to say outright that his work needs no continuation, that