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 here.) 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 here.) 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 firsthand element. The impression must be made upon me, upon my mind. The further we get away from this direct, firsthand 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 firsthand 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 (see here), not response to direct physical stimuli. And meaning exists only with reference to a context, which is excluded by any scheme
