arranged series of science studies added. In this study of science care should be taken to begin courses in which lessons are to be learned, and learned upon authority and with exactitude, later to be perfected by laboratory practise; such is, in my judgment, the finest kind of preliminary discipline for a man of research. For it takes a learned man to tell the truth with precision, even when he is its discoverer; and, moreover, only the learned man knows when he has discovered a new truth. Ability to study deeply and accurately is then the second essential qualification to the making of a man of research.
Thirdly, to undertake original research a man must be a trained investigator. He must know the methods by which other men have discovered truths and interpreted things. To learn this he must have gone through the exercise of a personal discovery of the meaning of things—have tested for himself the reality of the descriptions written in the books. Such training is best given in the laboratory; analysis and experiment leading to already known results must be gone over by the investigator in careful detail, and the steps of the progress, the associated conditions, the order of sequence of phenomena must be closely observed and recorded; and the relation of the phenomena to one another and the results of experiments clearly understood, formulated and, best of all, fully written out.
Fourth, the man of research should have a vivid imagination, which should be trained to be accurate and to be his servant, not his master. This faculty, I fear, is often trained out of men by what is called experience. Not only does the dry, matter of fact, world of every day tend to keep one down to thoughts of the immediate present, but the immensity of science and its practical applications, by the very abundance of the known facts, crowds out of use all mental pictures of hypothetical conditions not known to common experience. Nevertheless, as has been already noted, the very function of research is to go beyond the field of present knowledge, and in it the attention must be fixed steadily upon concepts, the realization of which has not yet been attained. The scientific imagination may be exercised and disciplined by the study of mathematics. The architect's work is a definite application of imagination to projecting new construction. What are called 'working hypotheses' are the results of this exercise of imagination in advancing research. The discipline of the faculty of imagination is necessary to enable the researcher to distinguish between his concepts of imagination and his concepts of experience. If he knows how to distinguish them, his imagination becomes his valuable assistant, if ignorant or unobservant of the difference, his results become speculative and ineffective.
A fifth trait marking the typical man of research is a wide, open mind. Philosophically he should be a whole man, not simply a one--
