As we shall see later, the development of experimentation as a method of knowledge makes possible and necessitates a radical transformation of the view just set forth. But before coming to that, we have to note the theory of experience and knowledge developed in the seventeenth and eighteenth centuries. In general, it presents us with an almost complete reversal of the classic doctrine of the relations of experience and reason. To Plato experience meant habituation, or the conservation of the net product of a lot of past chance trials. Reason meant the principle of reform, of progress, of increase of control. Devotion to the cause of reason meant breaking through the limitations of custom and getting at things as they really were. To the modern reformers, the situation was the other way around. Reason, universal principles, a priori notions, meant either blank forms which had to be filled in by experience, by sense observations, in order to get significance and validity; or else were mere indurated prejudices, dogmas imposed by authority, which masqueraded and found protection under august names. The great need was to break way from captivity to conceptions which, as Bacon put it, 'anticipated nature' and imposed merely human opinions upon her, and to resort to experience to find out what nature was like. Appeal to experience marked the breach with authority. It meant openness to new impressions; eagerness in discovery and invention instead of absorption in tabulating and systematizing received ideas and 'proving' them by means of the relations they sustained to one another. It was the irruption into the mind of the things as they really were, free from the veil cast over them by preconceived ideas.

The change was twofold. Experience lost the practical meaning which it had borne from the time of Plato. It ceased to mean ways of doing and being done to, and became a name for something intellectual and cognitive. It meant the apprehension of material which should ballast and check the exercise of reasoning. By the modern philosophic empiricist and by his opponent, experience has been looked upon just as a way of knowing. The only question was how good a way it is. The result was an even greater 'intellectualism' than is found in ancient philosophy, if that word be used to designate an emphatic and almost exclusive interest in knowledge in its isolation. Practice was not so much subordinated to knowledge as treated as a kind of tag-end or aftermath of knowledge. The educational result was only to confirm the exclusion of active pursuits from the school, save as they might be brought in for purely utilitarian ends—the acquisition by drill of certain habits. In the second place, the interest in experience as a means of basing truth upon objects, upon nature, led to looking at the mind as purely receptive. The more passive the mind is, the more truly objects will impress themselves upon it. For the mind to take a hand, so to speak, would be for it in the very process of knowing to vitiate true knowledge—to defeat its own purpose. The ideal was a maximum of receptivity.

Since the impressions made upon the mind by objects were generally termed sensations, empiricism thus became a doctrine of sensationalism—that is to say, a doctrine which identified knowledge with the reception and association of sensory impressions. In John Locke, the most influential of the empiricists, we find this sensationalism mitigated by a recognition of certain mental faculties, like discernment or discrimination, comparison, abstraction, and generalization which work up the material of sense into definite and organized forms and which even evolve new ideas on their own account, such as the fundamental conceptions of morals and mathematics. (See ante, ch. V p. 3.) But some of his successors, especially in France in the latter part of the eighteenth century, carried his doctrine to the limit; they regarded discernment and judgment as peculiar sensations made in us by the conjoint presence of other sensations. Locke had held that the mind is a blank piece of paper, or a wax tablet with nothing engraved on it at birth (a tabula rasa) so far as any contents of ideas were concerned, but had endowed it with activities to be exercised upon the material received. His French successors razed away the powers and derived them also from impressions received.

As we have earlier noted, this notion was fostered by the new interest in education as method of social reform. (See ante, ch. VII p. 4.) The emptier the mind to begin with, the more it may be made anything we wish by bringing the right influences to bear upon it. Thus Helvetius, perhaps the most extreme and consistent sensationalist, proclaimed that education could do anything—that it was omnipotent. Within the sphere of school instruction, empiricism found its directly beneficial office in protesting against mere book learning. If knowledge comes from the impressions made upon us by natural objects, it is impossible to procure knowledge without the use of objects which impress the mind. Words, all kinds of linguistic symbols, in the lack of prior presentations of objects with which they may be associated, convey nothing but sensations of their own shape and color—certainly not a very instructive kind of knowledge. Sensationalism was an extremely handy weapon with which to combat doctrines and opinions resting wholly upon tradition and authority. With respect to all of them, it set up a test: Where are the real objects from which these ideas and beliefs are received? If such objects could not be produced, ideas were explained as the result of false associations and combinations. Empiricism also insisted upon a first-hand element. The impression must be made upon me, upon my mind. The further we get away from this direct, first-hand source of knowledge, the more numerous the sources of error, and the vaguer the resulting idea.

As might be expected, however, the philosophy was weak upon the positive side. Of course, the value of natural objects and first-hand acquaintance was not dependent upon the truth of the theory. Introduced into the schools they would do their work, even if the sensational theory about the way in which they did it was quite wrong. So far, there is nothing to complain of. But the emphasis upon sensationalism also operated to influence the way in which natural objects were employed, and to prevent full good being got from them. "Object lessons" tended to isolate the mere sense-activity and make it an end in itself. The more isolated the object, the more isolated the sensory quality, the more distinct the sense-impression as a unit of knowledge. The theory worked not only in the direction of this mechanical isolation, which tended to reduce instruction to a kind of physical gymnastic of the sense-organs (good like any gymnastic of bodily organs, but not more so), but also to the neglect of thinking. According to the theory there was no need of thinking in connection with sense-observation; in fact, in strict theory such thinking would be impossible till afterwards, for thinking consisted simply in combining and separating sensory units which had been received without any participation of judgment.

As a matter of fact, accordingly, practically no scheme of education upon a purely sensory basis has ever been systematically tried, at least after the early years of infancy. Its obvious deficiencies have caused it to be resorted to simply for filling in 'rationalistic' knowledge (that is to say, knowledge of definitions, rules, classifications, and modes of application conveyed through symbols), and as a device for lending greater 'interest' to barren symbols. There are at least three serious defects of sensationalistic empiricism as an educational philosophy of knowledge. (a) The historical value of the theory was critical; it was a dissolvent of current beliefs about the world and political institutions. It was a destructive organ of criticism of hard and fast dogmas. But the work of education is constructive, not critical. It assumes not old beliefs to be eliminated and revised, but the need of building up new experience into intellectual habitudes as correct as possible from the start. Sensationalism is highly unfitted for this constructive task. Mind, understanding, denotes responsiveness to meanings (Ante, ch. III p. 2), not response to direct physical stimuli. And meaning exists only with reference to a context, which is excluded by any scheme which identifies knowledge with a combination of sense-impressions. The theory, so far as educationally applied, led either to a magnification of mere physical excitations or else to a mere heaping up of isolated objects and qualities.

(b) While direct impression has the advantage of being first hand, it also has the disadvantage of being limited in range. Direct acquaintance with the natural surroundings of the home environment, as a means of making real ideas about portions of the earth beyond the reach of the senses and as a means of arousing intellectual curiosity, is one thing. As an end-all and be-all of geographical knowledge it is fatally restricted. In precisely analogous fashion, beans, shoe pegs, and counters may be helpful aids to a realization of numerical relations, but when employed except as aids to thought—the apprehension of meaning—they become an obstacle to the growth of arithmetical understanding. They arrest growth on a low plane, the plane of specific physical symbols. Just as the race developed especial symbols as tools of calculation and mathematical reasonings, because the use of the fingers as numerical symbols got in the way, so the individual must progress from concrete to abstract symbols—that is, symbols whose meaning is realized only through conceptual thinking. And undue absorption at the outset in the physical object of sense hampers this growth.

(c) A thoroughly false psychology of mental development underlay sensationalistic empiricism. Experience is in truth a matter of activities, instinctive and impulsive, in their interactions with things. What even an infant 'experiences' is not a passively received quality impressed by an object, but the effect which some activity of handling, throwing, pounding, tearing, etc., has upon an object, and the consequent effect of the object upon the direction of activities. (See ante, ch. XI p. 1.) Fundamentally (as we shall see in more detail), the ancient notion of experience as a practical matter is truer to fact than the modern notion of it as a mode of knowing by means of sensations. The neglect of the deep-seated active and motor factors of experience is a fatal defect of the traditional empirical philosophy. Nothing is more uninteresting and mechanical than a scheme of object lessons which ignores and as far as may be excludes the natural tendency to learn about the qualities of objects by the uses to which they are put through trying to do something with them.

It is obvious, accordingly, that even if the philosophy of experience represented by modern empiricism had received more general theoretical assent than has been accorded to it, it could not have furnished a satisfactory philosophy of the learning process. Its educational influence was confined to injecting a new factor into the older curriculum, with incidental modifications of the older studies and methods. It introduced greater regard for observation of things directly and through pictures and graphic descriptions, and it reduced the importance attached to verbal symbolization. But its own scope was so meager that it required supplementation by information concerning matters outside of sense-perception and by matters which appealed more directly to thought. Consequently it left unimpaired the scope of informational and abstract, or 'rationalistic' studies.