This comment does not mean that Economic details are to be ignored except for classification, even by non-specialists. Far from that. It means that they are to be thoughtfully considered and accurately classified for further and comparative consideration. To illustrate: Mankind must be regarded as a class or category in Economics; but not according to personal or individual capabilities, idiosyncracies, or social, business, or legal status. To the business specialist, the personal qualities of an associate or assistant are important; but Economics as a comprehensive science, the science of all “mankind making a living,” knows those special distinctions only in a secondary sense. It is concerned primarily with the individual man only as a unit in the human mass--only from the fact that he is in the human category and not in one or more other Economic categories. So of all Economic facts. To study Economic details without reference to Economic generalizations might be likened to studying an alphabet without reference to language, or numerals without reference to mathematics. Economic problems are not problems of how one individual may make a living at the expense of others. Such problems belong in the plundering pursuits. In Economics the basic problem is how all may make a living at the expense of none. To that problem business details give no clew, unless the details be assigned to fundamental Economic categories. Piling up details without assigning them is, as Henry James the Elder wisely expressed it, to “sink the truth in endless confusion.” The last person in all the world from whom to get the basic facts of Economics is the business specialist, for he habitually limits his observations to his own specialty. Perhaps, however, a certain type of Economic teacher may be equally untrustworthy in that respect--the teacher who, though he imitates the physical scientist in devotion to details, disregards the physical scientist’s fidelity to the relations of cause and effect.