WUNDT AND 'PURE SELP-OBSERVATION '. 393 Furthermore, the conditions for complete reproduction may thus be discovered, be they nearness in time, association, intensity of experience, interest, disposition, or repetition. Indeed, the outlines may be exhaustively studied until our conclusions on the subject exhaust the inquiry, that is, we can learn how outlines are recalled and we can determine the conditions which produce them. We are at last not only able to predict in detail, but to experimentally repeat everything. What is more, the whole matter may be ex- perimentally studied. We observe a selected object more or less frequently under conditions which we more or less vary, and we note the changes in the image. To say that such observation or experiment is impossible I am referring to visual outlines is to assert something for which proof should be forthcoming, especially when there are persons who seriously contend for the possibility, as were those who answered Galton's questions. In any case, the present writer is convinced that no external observation is more easy or reliable than internal observation is in this matter. In internal observation I cannot conceive of not being able to recall the many individuals I know and steadily observing their features, which in some cases are traceable in detail and in others are not discernible at all. In certain instances where there is but the merest fugitive shadow noticeable I cannot perhaps tell the story of the particular image ; but in many I can account for all that is material. I learn how superficial observation leads to the fixing of few features ; how observation which is only directed to im- mediate satisfaction has little value for the memory ; how through superficial recall of an image or attending to it partially or furtively, it is degraded ; I notice how recency and familiarity almost repeat the original experience to a confusing degree ; and how time, unchecked by repetition, leads to the gradual disintegra- tion of the image. Or examine the matter from the experimental point of view. Suppose it is a question of verifying Galton's theory that a general idea is a composite image, constituted in any particular instance, say, of all the rivers or mountains I have seen. First, I thoroughly test my memory. Then I take lines of different lengths, thick- nesses and inclinations, and note whether they fuse into a composite image. Having done with single lines, I may experiment with figures, from simple to complex. Suppose, then, I find not a single fact, out of many thousands systematically collected, which supports the theory, and everything to show that images never overlap, shall I have a doubt in rejecting Galton's composite image theory on the ground that "conscious contents are . . . fleeting occurrences, in continual flux and change, ... at the opposite pole from permanent objects"? Surely, any ordinary scientific solution in physics, physiology or chemistry is no more satisfactory, simple or exact than the results of the method em- ployed above, or is it a fact that all scientific work outside psychology say, in physiology is always mathematically de-
