In all this, there is no difference of kind between the methods of science and those of the plain man. The difference is the greater control in science of the statement of the problem, and of the selection and use of relevant material, both sensible or ideational. The two are related to each other just as the hit-or-miss, trial-and-error inventions of uncivilized man stand to the deliberate and consecutively persistent efforts of a modern inventor to produce a certain complicated device for doing a comprehensive piece of work. Neither the plain man nor the scientific inquirer is aware, as he engages in his reflective activity, of any transition from one sphere of existence to another. He knows no two fixed worlds--reality on one side and mere subjective ideas on the other; he is aware of no gulf to cross. He assumes uninterrupted, free, and fluid passage from ordinary experience to abstract thinking, from thought to fact, from things to theories and back again. Observation passes into development of hypothesis; deductive methods pass to use in description of the particular; inference passes into action with no sense of difficulty save those found in the particular task in question. The fundamental assumption is _continuity_ in and of experience. This does not mean that fact is confused with idea, or observed datum with voluntary hypothesis, theory with doing, any more than a traveler confuses land and water when he journeys from one to the other. It simply means that each is placed and used with reference to service rendered the other, and with reference to future use of the other. Only the epistemological spectator is aware of the fact that the everyday man and the scientific man in this free and easy intercourse are rashly assuming the right to glide over a cleft in the very structure of reality. This fact raises a query not favorable to the epistemologist. Why is it that the scientific man, who is constantly plying his venturous traffic of exchange of facts for ideas, of theories for laws, of real things for hypotheses, should be so wholly unaware of the radical and generic (as distinct from specific) difficulty of the undertakings in which he is engaged? We thus come afresh to our inquiry: Does not the epistemological logician unwittingly transfer the specific difficulty which always faces the scientific man--the difficulty in detail of correct and adequate translation back and forth of _this_ set of facts and _this_ group of ideas--into a totally different problem of the wholesale relation of thought at large with reality in general? If such be the case, it is clear that the very way in which the epistemological type of logic states the problem of thinking, in relation both to empirical antecedents and to objective truth, makes that problem insoluble. Working terms, terms which as working are flexible and historic, relative, are transformed into absolute, fixed, and predetermined forms of being.