The attitude of research is necessarily toward the future. The application of science to the practical affairs of life, as in the stationary engine, or telephone, does not differ in principle from the determination of wave-lengths of light through the experimental control of the laboratory. Science lives only in arranging for new contacts, new insights. The school of Kant agrees with that of Mill in asserting that judgment must, in order to be judgment, be synthetic or instructive; it must extend, inform, and purvey. When we recognize that this service of judgment in effecting growth of experience is not accidental, but that judgment means exactly the devising and using of suitable instrumentalities for this end, we remark that the so-called practical uses of science are only the further and freer play of the intrinsic movement of discovery itself.
We began with the assumption that thought is to be interpreted as a doubt-inquiry function, conducted for the purpose of arriving at that mental equilibrium known as assurance or knowledge. We assumed that various stages of thinking could be marked out according to the amount of play which they give to doubt, and the consequent sincerity with which thinking is identified with free inquiry. Modern scientific procedure, as just set forth, seems to define the ideal or limit of this process. It is inquiry emancipated, universalized, whose sole aim and criterion is discovery, and hence it marks the terminus of our description. It is idle to conceal from ourselves, however, that scientific procedure as a practical undertaking, has not as yet reflected itself into any coherent and generally accepted theory of thinking, into any accepted doctrine of logic which is comparable to the Aristotelian. Kant's conviction that logic is a "complete and settled" science, which with absolutely "certain boundaries has gained nothing and lost nothing since Aristotle," is startlingly contradicted by the existing state of discussion of logical doctrine. The simple fact of the case is that there are at least three rival theories on the ground, each claiming to furnish the sole proper interpretation of the actual procedure of thought.
The Aristotelian logic is far from having withdrawn its claim. It still offers its framework as that into which the merely "empirical" results of observation and experimental inquiry must be fitted if they are to be regarded as really "proved." Another school of logicians, starting professedly from modern psychology, discredits the whole traditional industry and reverses the Aristotelian theory of validity; it holds that only particular facts are self-supporting, and that the authority allowed to general principles is derivative and second hand. A third school of philosophy claims, by analysis of science and experience, to justify the conclusion that the universe itself is a construction of thought, giving evidence throughout of the pervasive and constitutive action of reason, and holds, consequently, that our logical processes are simply the reading off or coming to consciousness of the inherently rational structure already possessed by the universe in virtue of the presence within it of this pervasive and constitutive action of thought. It thus denies both the claim of the traditional logic, that matters of experienced fact are mere particulars having their rationality in an external ground, and the claim of the empirical logic, that thought is just a gymnastic by which we vault from one presented fact to another remote in space and time.
Which of the three doctrines is to be regarded as the legitimate exponent of the procedure of thought manifested in modern science? While the Aristotelian logic is willing to waive a claim to be regarded as expounder of the actual procedure, it still insists upon its right to be regarded as the sole ultimate umpire of the validity or proved character of the results reached. But the empirical and transcendental logics stand face to face as rivals, each asserting that it alone tells the story of what science does and how it does it.
With the consciousness of this conflict my discussion in its present, or descriptive, phase must cease. Its close, however, suggests a further question. In so far as we adopt the conception that thinking is itself a doubt-inquiry process, must we not deny the claims of all of the three doctrines to be the articulate voicing of the methods of experimental science? Do they not all agree in setting up something fixed outside inquiry, supplying both its material and its limit? That the first principle and the empirical matters of fact of the Aristotelian logic fall outside the thinking process, and condemn the latter to a purely external and go-between agency, has been already sufficiently descanted upon. But it is also true that the fixed particulars, given facts, or sensations—whatever the empirical logician starts from—are material given ready-made to the thought-process, and externally limiting inquiry, instead of being distinctions arising within and because of search for truth. Nor, as regards this point, is the transcendental in any position to throw stones at the empirical logic. Thought "in itself" is so far from a process of inquiry that it is taken to be the eternal, fixed structure of the universe; our thinking, involving doubt and investigation, is due wholly to our "finite," imperfect character, which condemns us to the task of merely imitating and reinstating "thought" in itself, once and forever complete, ready-made, fixed.
The practical procedure and practical assumptions of modern experimental science, since they make thinking essentially and not merely accidentally a process of discovery, seem irreconcilable with both the empirical and transcendental interpretations. At all events there is here sufficient discrepancy to give occasion for further search: Does not an account of thinking, basing itself on modern scientific procedure, demand a statement in which all the distinctions and terms of thought—judgment, concept, inference, subject, predicate, and copula of judgment, etc., ad infinitum—shall be interpreted simply and entirely as distinctive functions or divisions of labor within the doubt-inquiry process?