history of the far-Oriental peoples, many questions of cause and effect are found to be sufficiently disposed of when worked out in the like terms of generation, growth and quasi-physiological mutation. To modern inquiry explanations in these terms, other than those of physically effective work, are provisional at the best, and are held to only as awaiting a final solution in a materially, mechanistically competent way. And what is alone materially competent in the modern scientific apprehension is such an explanation as will make things plain in terms of matter and motion, working a change in the constitution of things by displacement through contact and pressure. Causation is conceived as manual work,--to use a French term, it is a _remaniement_ of raw materials at hand. Physiological or chemical explanations must finally be recast in terms of physics, to satisfy the modern scientist’s sense of finality, and physics must be made to run in terms of impact, pressure, displacement in space, regrouping of material particles, coördinated movements and a shifting of equilibrium. Through all this runs the concomitant requirement of quantivalence, statable in statistical form. The scientist’s results are not finally merchantable, on the scientific exchange, until they have been reduced to such terms of accountancy as would be comprehensible to the man trained in the merchandising traffic of the petty trade, for whose conviction things must be punctiliously rated in exchange value. But, as has been noted above, it is only as an expedient of scientific accountancy that the facts under inquiry are kept account of in an itemised bill of values. This meticulous statistical accountancy is necessary to safeguard the accuracy of the work done and its conformity with the facts in hand; but the work so done handles these facts as active factors which go efficiently to the production of the results observed. The cause is conceived to produce the effect, somewhat after the fashion in which a skilled workman produces a finished article of trade. But when the scientist has set forth the operations and working conditions that have brought forth the effects which he is engaged in explaining, he must also, in order to the conviction of his fellow craftsmen, show a statistically itemised statement of receipts and expenditures covering the facts engaged,--in quantitative values he must show that the costs are balanced by the values that emerge in the finished product of that workmanlike process of causation whose recondite nature and course he has so laid bare to the light of understanding.