It is sometimes felt that these methods which savour strongly of catching the patient tripping, while they may unearth some interesting details of his past life, do no more than exhibit under a strong magnifying glass a few minute excrescences upon his otherwise fair mental countenance. But it should be pointed out that nobody who has ever honestly collected together and compared the memories which have coalesced to compose a dozen of his dreams—especially if he has done so with the help and under the cross-examination of a candid friend who knows him well—will maintain that the material thus found is unimportant. As Professor Freud says, “The dream never occupies itself with trifles.” It is probably just because the thoughts and desires underlying the dreams have been refused their normal outlet, that they express themselves in such bizarre forms. Moreover, the fact should not be overlooked that in other sciences—including the most exact, the physical sciences—the most profoundly important general conclusions are often arrived at by the examination of unusual phenomena, of nature “caught tripping.” The study of the thunderstorm was the foundation of our present knowledge of that great force which is active not only in thunderstorms but throughout all matter. Observation of the sporadic and relatively unusual volcanic eruptions of the mind may prove to be an important foundation of our future knowledge of general psychology. As in the inorganic, so in the organic world, there is no sharp line dividing normal from abnormal, and the unusual phenomenon is sometimes simpler and more easily studied than the usual, as “Sherlock Holmes” was so fond of demonstrating.[43] From a scientific standpoint, then, we have every justification for pressing to the utmost our study of the unusual mental phenomena exhibited by the patient, and for our belief that their nature is not unimportant, but highly significant for therapeutical purposes. Another objection, however, is frequently levelled against such a procedure, from quite a different direction, or rather from a number of directions. This objection can be expressed simply in words, such as “One ought not to probe so deeply into a patient’s innermost mental life,” and is not to be met by a single argument. The reason is that it is polyhedral in form, and that each of its faces or aspects must be considered separately. For it should be obvious to everyone that such an objection cannot be flippantly waved away. The aspects of this question which seem to have more particularly appealed to the critics of the method which we are describing, are at least four in number, which we may describe as the æsthetic, social, medical and moral.