And of a sudden a new caste of men appears, who say, All these are nonsense, and are to be left behind. This is the deductive way of thinking (though wherein lies the difference between the inductive and the deductive way of thinking, nobody ever has been able to understand), and this is also the method of the theological and metaphysical periods. All that men have understood by inward experience, and have related to each other concerning the consciousness of the law of their own life (functional activity, in their cant phrase); all that from the beginning of the world has been done in this direction by the greatest intellects of mankind,--all these are trifles, having no weight whatever. According to this new teaching, you are the cell of an organism, and the problem of your reasonable activity consists in trying to ascertain your functional activity. In order to ascertain this, you must make observations outside yourself. The fact that you are a cell which thinks, suffers, speaks, and understands, and that for that very reason you can inquire of another similar speaking, suffering cell whether he or she suffers and rejoices in the same way as yourself, and that thus you may verify your own experience; and the fact that you may make use of what the speaking cells, who lived and suffered before you wrote on the subject; and your knowledge that millions of cells agreeing with what the past cells have written, confirm your own experience, that you yourself are a living cell, who always, by a direct inward experience, apprehend the correctness or incorrectness of your own functional activity,--all this means nothing, we are told: it is all a false and evil method. The true scientific method is this: If you wish to learn in what your functional activity consists, what is your destiny and welfare, and what the destiny of mankind, and of the whole world, then first you must cease to listen to the voice and demands of your conscience and of your reason, which manifest themselves inwardly to you and to your fellow-men; you must leave off believing all that the great teachers of humanity have said about their own conscience and reason, and you must consider all this to be nonsense, and begin at the beginning. And in order to begin from the beginning, you have to observe through a microscope the movements of amoebæ and the cells of tape-worms; or, still easier, you must believe everything that people with the diploma of infallibility may tell you about them. And observing the movements of these amoebæ and cells, or reading what others have seen, you must ascribe to these cells your own human feelings and calculations as to what they desire, what are their tendencies, their reflections and calculations, their habits; and from these _observations_ (in which each word contains some mistake of thought or of expression), according to analogy, you must deduce what is your own destiny, and what that of other cells similar to you.