Science is a name for knowledge in its most characteristic form. It represents in its degree, the perfected outcome of learning,—its consummation. What is known, in a given case, is what is sure, certain, settled, disposed of; that which we think with rather than that which we think about. In its honorable sense, knowledge is distinguished from opinion, guesswork, speculation, and mere tradition. In knowledge, things are ascertained; they are so and not dubiously otherwise. But experience makes us aware that there is difference between intellectual certainty of subject matter and our certainty. We are made, so to speak, for belief; credulity is natural. The undisciplined mind is averse to suspense and intellectual hesitation; it is prone to assertion. It likes things undisturbed, settled, and treats them as such without due warrant. Familiarity, common repute, and congeniality to desire are readily made measuring rods of truth. Ignorance gives way to opinionated and current error,—a greater foe to learning than ignorance itself. A Socrates is thus led to declare that consciousness of ignorance is the beginning of effective love of wisdom, and a Descartes to say that science is born of doubting.

We have already dwelt upon the fact that subject matter, or data, and ideas have to have their worth tested experimentally: that in themselves they are tentative and provisional. Our predilection for premature acceptance and assertion, our aversion to suspended judgment, are signs that we tend naturally to cut short the process of testing. We are satisfied with superficial and immediate short-visioned applications. If these work out with moderate satisfactoriness, we are content to suppose that our assumptions have been confirmed. Even in the case of failure, we are inclined to put the blame not on the inadequacy and incorrectness of our data and thoughts, but upon our hard luck and the hostility of circumstance. We charge the evil consequence not to the error of our schemes and our incomplete inquiry into conditions (thereby getting material for revising the former and stimulus for extending the latter) but to untoward fate. We even plume ourselves upon our firmness in clinging to our conceptions in spite of the way in which they work out.

Science represents the safeguard of the race against these natural propensities and the evils which flow from them. It consists of the special appliances and methods which the race has slowly worked but in order to conduct reflection under conditions whereby its procedures and results are tested. It is artificial (an acquired art), not spontaneous; learned, not native. To this fact is due the unique, the invaluable place of science in education, and also the dangers which threaten its right use. Without initiation into the scientific spirit one is not in possession of the best tools which humanity has so far devised for effectively directed reflection. One in that case not merely conducts inquiry and learning without the use of the best instruments, but fails to understand the full meaning of knowledge. For he does not become acquainted with the traits that mark off opinion and assent from authorized conviction. On the other hand, the fact that science marks the perfecting of knowing in highly specialized conditions of technique renders its results, taken by themselves, remote from ordinary experience—a quality of aloofness that is popularly designated by the term abstract. When this isolation appears in instruction, scientific information is even more exposed to the dangers attendant upon presenting ready-made subject matter than are other forms of information.

Science has been defined in terms of method of inquiry and testing. At first sight, this definition may seem opposed to the current conception that science is organized or systematized knowledge. The opposition, however, is only seeming, and disappears when the ordinary definition is completed. Not organization but the kind of organization effected by adequate methods of tested discovery marks off science. The knowledge of a farmer is systematized in the degree in which he is competent. It is organized on the basis of relation of means to ends—practically organized. Its organization as knowledge (that is, in the eulogistic sense of adequately tested and confirmed) is incidental to its organization with reference to securing crops, live-stock, etc. But scientific subject matter is organized with specific reference to the successful conduct of the enterprise of discovery, to knowing as a specialized undertaking.

Reference to the kind of assurance attending science will shed light upon this statement. It is rational assurance,—logical warranty. The ideal of scientific organization is, therefore, that every conception and statement shall be of such a kind as to follow from others and to lead to others. Concepts and propositions mutually imply and support one another. This double relation of "leading to and confirming" is what is meant by the terms logical and rational. The everyday conception of water is more available for ordinary uses of drinking, washing, irrigation, etc., than the chemist's notion of it. The latter's description of it as  is superior from the standpoint of place and use in inquiry. It states the nature of water in a way which connects it with knowledge of other things, indicating to one who understands it how the knowledge is arrived at and its bearings upon other portions of knowledge of the structure of things. Strictly speaking, it does not indicate the objective relations of water any more than does a statement that water is transparent, fluid, without taste or odor, satisfying to thirst, etc. It is just as true that water has these relations as that it is constituted by two molecules of hydrogen in combination with one of oxygen. But for the particular purpose of conducting discovery with a view to ascertainment of fact, the latter relations are fundamental. The more one emphasizes organization as a mark of science, then, the more he is committed to a recognition of the primacy of method in the definition of science. For method defines the kind of organization in virtue of which science is science.