Before that epoch the animus of a science was, on the whole, the animus of taxonomy; the consistent end of scientific inquiry was definition and classification,--as it still continues to be in such fields of science as have not been affected by the modern notion of consecutive change. The scientists of that era looked to a final term, a consummation of the changes which provoked their inquiry, as well as to a first beginning of the matters with which their researches were concerned. The questions of science were directed to the problem, essentially classificatory, of how things had been in the presumed primordial stable equilibrium out of which they, putatively, had come, and how they should be in the definitive state of settlement into which things were to fall as the outcome of the play of forces which intervened between this primordial and the definitive stable equilibrium. To the pre-Darwinian taxonomists the center of interest and attention, to which all scientific inquiry must legitimately converge, was the body of natural laws governing phenomena under the rule of causation. These natural laws were of the nature of rules of the game of causation. They formulated the immutable relations in which things "naturally" stood to one another before causal disturbance took place between them, the orderly unfolding of the complement of causes involved in the transition over this interval of transient activity, and the settled relations that would supervene when the disturbance had passed and the transition from cause to effect had been consummated,--the emphasis falling on the consummation. The characteristic feature by which post-Darwinian science is contrasted with what went before is a new distribution of emphasis, whereby the process of causation, the interval of instability and transition between initial cause and definitive effect, has come to take the first place in the inquiry; instead of that consummation in which causal effect was once presumed to come to rest. This change of the point of view was, of course, not abrupt or catastrophic. But it has latterly gone so far that modern science is becoming substantially a theory of the process of consecutive change, which is taken as a sequence of cumulative change, realized to be self-continuing or self-propagating and to have no final term. Questions of a primordial beginning and a definitive outcome have fallen into abeyance within the modern sciences, and such questions are in a fair way to lose all claim to consideration at the hands of the scientists. Modern science is ceasing to occupy itself with the natural laws--the codified rules of the game of causation--and is concerning itself wholly with what has taken place and what is taking place. * * * * *