For many years past astronomy has been needing a careful revision of the Kant and Laplace’s hypothesis; but no theory is yet forthcoming which would compel general acceptance. Geology surely has made, wonderful progress in the reconstitution of the paleontological record, but dynamical geology progresses at a despairingly slow rate; while all future progress in the great question as to the laws of distribution of living organisms on the surface of the earth is hampered by the want of knowledge as to the extension of glaciation during the Quaternary epoch. 194
In short, in each branch of science a revision of the current theories as well as new wide generalisations are wanted. And if the, revision requires some of that inspiration of genius which moved Galileo and Newton, and which depends in its appearance upon general causes of human development, it requires also an increase in the number of scientific workers. When facts contradictory to current theories become numerous, the theories must be revised (we saw it in Darwin’s case), and thousands of simple intelligent workers in science are required to accumulate the necessary facts.
Immense regions of the earth still remain unexplored; the study of the geographical distribution of animals and plants meets with stumbling-blocks at every step. Travellers cross continents, and do not know even how to determine the latitude nor how to manage a barometer. Physiology, both of plants and animals, psycho-physiology, and the psychological faculties of man and animals are so many branches of knowledge requiring more data of the simplest description. History remains a fable convenue chiefly because it wants fresh ideas, but also because it wants scientifically thinking workers to reconstitute the life of past centuries in the same way as Thorold Rogers or Augustin Thierry have done it for separate epochs.