Drawing of Mars as seen on November 18th, 1894 (Long. 325° on the meridian) by Mr. Perceval Lowell at the Flagstaff Observatory, Arizona, U.S.A., shewing ‘twin’ or ‘double’ canals, connected northwards with the ‘Mare Icarium.’ The two figures here reproduced only give a small portion of the system of canals, oases and seas of the planet Mars, mapped by Mr. Lowell.] 18. THE INVESTIGATION OF THE HUMAN MIND. In such a desultory survey as that on which I have ventured, of Man’s kingdom and its dangers, it occurs to me to mention another area upon which it seems urgent that the activities of nature-searchers should be immediately turned with increased power and number. The experimental study of his body and of that of animals has been carried far and with valuable results by inquiring Man. But a singularly small amount of attention has as yet been given to the investigation of Man’s mind as a natural phenomenon and one which can be better understood to the immense advantage of the race. The mind of Man--it matters not for my immediate argument whether it be regarded as having arisen normally or abnormally from the mind of animals--is obviously the one and all-powerful instrument with which he has contended, and is destined hereafter to contend, against extra-human Nature. It is no less important for him to know the quality, the capacity, the mode of operation of this instrument, its beginnings and its limitations, than it is for him to know the minutest details of the workings of Nature. Just as much in the one case as in the other, it is impossible for him to trust to the imperfect analysis made by ancient races of men and the traditions and fancies handed down in old writings--produced by generations who had not arrived at the method of investigation which we now can apply. Experiment upon the mental processes of animals and of Man is greatly needed. Only here and there has anything been done in this direction. Most promising results have been obtained by such observations as those on hypnotism and on various diseased and abnormal states of the brain. But the subject is so little explored that wild and untested assertions as to the powers of the mind are current and have given rise to strange beliefs, accepted by many seriously-intentioned men and women. We boldly operate upon the minds of children in our systems of education without really knowing what we are doing. We blindly assume that the owners of certain minds, traditionally trained in amusing elegancies, are fit to govern their fellow-men and administer vast provinces; we assume that the discovery and comprehension of Nature’s processes must be the work of very few and peculiar minds; that if we take care of the body the mind will take care of itself. We know really nothing of the heredity of mental qualities, nor how to estimate their presence or absence in the young so as to develop the mind to greatest advantage. We know