As the instrumental theory is favorable to high esteem for impartial and disinterested inquiry, so, contrary to the impressions of some critics, it sets much store upon the apparatus of deduction. It is a strange notion that because one says that the cognitive value of conceptions, definitions, generalizations, classifications and the development of consecutive implications is not self-resident, that therefore one makes light of the deductive function, or denies its fruitfulness and necessity. The instrumental theory only attempts to state with some scrupulousness where the value is found and to prevent its being sought in the wrong place. It says that knowing begins with specific observations that define the problem and ends with specific observations that test a hypothesis for its solution. But that the idea, the meaning, which the original observations suggest and the final ones test, itself requires careful scrutiny and prolonged development, the theory would be the last to deny. To say that a locomotive is an agency, that it is intermediate between a need in experience and its satisfaction, is not to depreciate the worth of careful and elaborate construction of the locomotive, or the need of subsidiary tools and processes that are devoted to introducing improvements into its structure. One would rather say that because the locomotive is intermediary in experience, not primary and not final, it is impossible to devote too much care to its constructive development.
Such a deductive science as mathematics represents the perfecting of method. That a method to those concerned with it should present itself as an end on its own account is no more surprising than that there should be a distinct business for making any tool. Rarely are those who invent and perfect a tool those who employ it. There is, indeed, one marked difference between the physical and the intellectual instrumentality. The development of the latter runs far beyond any immediately visible use. The artistic interest in perfecting the method by itself is strong—as the utensils of civilization may themselves become works of finest art. But from the practical standpoint this difference shows that the advantage as an instrumentality is on the side of the intellectual tool. Just because it is not formed with a special application in mind, because it is a highly generalized tool, it is the more flexible in adaptation to unforeseen uses. It can be employed in dealing with problems that were not anticipated. The mind is prepared in advance for all sorts of intellectual emergencies, and when the new problem occurs it does not have to wait till it can get a special instrument ready.
More definitely, abstraction is indispensable if one experience is to be applicable in other experiences. Every concrete experience in its totality is unique; it is itself, non-reduplicable. Taken in its full concreteness, it yields no instruction, it throws no light. What is called abstraction means that some phase of it is selected for the sake of the aid it gives in grasping something else. Taken by itself, it is a mangled fragment, a poor substitute for the living whole from which it is extracted. But viewed teleologically or practically, it represents the only way in which one experience can be made of any value for another—the only way in which something enlightening can be secured. What is called false or vicious abstractionism signifies that the function of the detached fragment is forgotten and neglected, so that it is esteemed barely in itself as something of a higher order than the muddy and irregular concrete from which it was wrenched. Looked at functionally, not structurally and statically, abstraction means that something has been released from one experience for transfer to another. Abstraction is liberation. The more theoretical, the more abstract, an abstraction, or the farther away it is from anything experienced in its concreteness, the better fitted it is to deal with any one of the indefinite variety of things that may later present themselves. Ancient mathematics and physics were much nearer the gross concrete experience than are modern. For that very reason they were more impotent in affording any insight into and control over such concretes as present themselves in new and unexpected forms.
Abstraction and generalization have always been recognized as close kin. It may be said that they are the negative and positive sides of the same function. Abstraction sets free some factor so that it may be used. Generalization is the use. It carries over and extends. It is always in some sense a leap in the dark. It is an adventure. There can be no assurance in advance that what is extracted from one concrete can be fruitfully extended to another individual case. Since these other cases are individual and concrete they must be dissimilar. The trait of flying is detached from the concrete bird. This abstraction is then carried over to the bat, and it is expected in view of the application of the quality to have some of the other traits of the bird. This trivial instance indicates the essence of generalization, and also illustrates the riskiness of the proceeding. It transfers, extends, applies, a result of some former experience to the reception and interpretation of a new one. Deductive processes define, delimit, purify and set in order the conceptions through which this enriching and directive operation is carried on, but they cannot, however perfect, guarantee the outcome.
The pragmatic value of organization is so conspicuously enforced in contemporary life that it hardly seems necessary to dwell upon the instrumental significance of classification and systematization. When the existence of qualitative and fixed species was denied to be the supreme object of knowledge, classification was often regarded, especially by the empirical school, as merely a linguistic device. It was convenient for memory and communication to have words that sum up a number of particulars. Classes were supposed to exist only in speech. Later, ideas were recognized as a kind of tertium quid between things and words. Classes were allowed to exist in the mind as purely mental things. The critical disposition of empiricism is well exemplified here. To assign any objectivity to classes was to encourage a belief in eternal species and occult essences and to strengthen the arms of a decadent and obnoxious science—a point of view well illustrated in Locke. General ideas are useful in economizing effort, enabling us to condense particular experiences into simpler and more easily carried bunches and making it easier to identify new observations.
So far nominalism and conceptualism—the theory that kinds exist only in words or in ideas—was on the right track. It emphasized the teleological character of systems and classifications, that they exist for the sake of economy and efficiency in reaching ends. But this truth was perverted into a false notion, because the active and doing side of experience was denied or ignored. Concrete things have ways of acting, as many ways of acting as they have points of interaction with other things. One thing is callous, unresponsive, inert in the presence of some other things; it is alert, eager, and on the aggressive with respect to other things; in a third case, it is receptive, docile. Now different ways of behaving, in spite of their endless diversity, may be classed together in view of common relationship to an end. No sensible person tries to do everything. He has certain main interests and leading aims by which he makes his behavior coherent and effective. To have an aim is to limit, select, concentrate, group. Thus a basis is furnished for selecting and organizing things according as their ways of acting are related to carrying forward pursuit. Cherry trees will be differently grouped by woodworkers, orchardists, artists, scientists and merry-makers. To the execution of different purposes different ways of acting and reacting on the part of trees are important. Each classification may be equally sound when the difference of ends is borne in mind.
Nevertheless there is a genuine objective standard for the goodness of special classifications. One will further the cabinetmaker in reaching his end while another will hamper him. One classification will assist the botanist in carrying on fruitfully his work of inquiry, and another will retard and confuse him. The teleological theory of classification does not therefore commit us to the notion that classes are purely verbal or purely mental. Organization is no more merely nominal or mental in any art, including the art of inquiry, than it is in a department store or railway system. The necessity of execution supplies objective criteria. Things have to be sorted out and arranged so that their grouping will promote successful action for ends. Convenience, economy and efficiency are the bases of classification, but these things are not restricted to verbal communication with others nor to inner consciousness; they concern objective action. They must take effect in the world.
At the same time, a classification is not a bare transcript or duplicate of some finished and done-for arrangement pre-existing in nature. It is rather a repertory of weapons for attack upon the future and the unknown. For success, the details of past knowledge must be reduced from bare facts to meanings, the fewer, simpler and more extensive the better. They must be broad enough in scope to prepare inquiry to cope with any phenomenon however unexpected. They must be arranged so as not to overlap, for otherwise when they are applied to new events they interfere and produce confusion. In order that there may be ease and economy of movement in dealing with the enormous diversity of occurrences that present themselves, we must be able to move promptly and definitely from one tool of attack to another. In other words, our various classes and kinds must be themselves classified in graded series from the larger to the more specific. There must not only be streets, but the streets must be laid out with reference to facilitating passage from any one to any other. Classification transforms a wilderness of by-ways in experience into a well-ordered system of roads, promoting transportation and communication in inquiry. As soon as men begin to take foresight for the future and to prepare themselves in advance to meet it effectively and prosperously, the deductive operations and their results gain in importance. In every practical enterprise there are goods to be produced, and whatever eliminates wasted material and promotes economy and efficiency of production is precious.
Little time is left to speak of the account of the nature of truth given by the experimental and functional type of logic. This is less to be regretted because this account is completely a corollary from the nature of thinking and ideas. If the view held as to the latter is understood, the conception of truth follows as a matter of course. If it be not understood, any attempt to present the theory of truth is bound to be confusing, and the theory itself to seem arbitrary and absurd. If ideas, meanings, conceptions, notions, theories, systems are instrumental to an active reorganization of the given environment, to a removal of some specific trouble and perplexity, then the test of their validity and value lies in accomplishing this work. If they succeed in their office, they are reliable, sound, valid, good, true. If they fail to clear up confusion, to eliminate defects, if they increase confusion, uncertainty and evil when they are acted upon, then are they false. Confirmation, corroboration, verification lie in works, consequences. Handsome is that handsome does. By their fruits shall ye know them. That which guides us truly is true—demonstrated capacity for such guidance is precisely what is meant by truth. The adverb "truly" is more fundamental than either the adjective, true, or the noun, truth. An adverb expresses a way, a mode of acting. Now an idea or conception is a claim or injunction or plan to act in a certain way as the way to arrive at the clearing up of a specific situation. When the claim or pretension or plan is acted upon it guides us truly or falsely; it leads us to our end or away from it. Its active, dynamic function is the all-important thing about it, and in the quality of activity induced by it lies all its truth and falsity. The hypothesis that works is the true one; and truth is an abstract noun applied to the collection of cases, actual, foreseen and desired, that receive confirmation in their works and consequences.
So wholly does the worth of this conception of truth depend upon the correctness of the prior account of thinking that it is more profitable to consider why the conception gives offence than to expound it on its own account. Part of the reason why it has been found so obnoxious is doubtless its novelty and defects in its statement. Too often, for example, when truth has been thought of as satisfaction, it has been thought of as merely emotional satisfaction, a private comfort, a meeting of purely personal need. But the satisfaction in question means a satisfaction of the needs and conditions of the problem out of which the idea, the purpose and method of action, arises. It includes public and objective conditions. It is not to be manipulated by whim or personal idiosyncrasy. Again when truth is defined as utility, it is often thought to mean utility for some purely personal end, some profit upon which a particular individual has set his heart. So repulsive is a conception of truth which makes it a mere tool of private ambition and aggrandizement, that the wonder is that critics have attributed such a notion to sane men. As matter of fact, truth as utility means service in making just that contribution to reorganization in experience that the idea or theory claims to be able to make. The usefulness of a road is not measured by the degree in which it lends itself to the purposes of a highwayman. It is measured by whether it actually functions as a road, as a means of easy and effective public transportation and communication. And so with the serviceableness of an idea or hypothesis as a measure of its truth.