We see with what broad and far-reaching conclusions the new philosophy closes. In the forcible poetry of the pages just quoted its original accent rings deep and pure. Some of its leading theses, moreover, are noted here. But now we must discover the solid foundation of underlying fact.
Let us take first the fact of biological evolution. Why has it been selected as the basis of the system? Is it really a fact, or is it only a more or less conjectural and plausible theory?
Notice in the first instance that the argument from evolution appears at least as a weapon of co-ordination and research admitted in our day by all philosophers, rejected only on the inspiration of preconceived ideas which are completely unscientific; and that it succeeds in the task allotted to it is doubtless already the proof that it responds to some part of reality. And besides, we can go further. "The idea of transformism is already contained in germ in the natural classification of organised beings. The naturalist brings resembling organisms together, divides the group into sub-groups, within which the resemblance is still greater, and so on; throughout the operation, the characteristics of the group appear as general themes upon which each of the sub-groups executes its particular variations.
"Now this is precisely the relation we find in the animal world and in the vegetable world between that which produces and what is produced; on the canvas bequeathed by the ancestor to his posterity, and possessed in common by them, each broiders his original pattern." ("Creative Evolution", pages 24-25.)
We may, it is true, ask ourselves whether the genealogical method permits results so far divergent as those presented to us by variety of species. But embryology answers by showing us the highest and most complex forms of life attained every day from very elementary forms; and palaeontology, as it develops, allows us to witness the same spectacle in the universal history of life, as if the succession of phases through which the embryo passes were only a recollection and an epitome of the complete past whence it has come. In addition, the phenomena of sudden changes, recently observed, help us to understand more easily the conception which obtrudes itself under so many heads, by diminishing the importance of the apparent lacunae in genealogical continuity. Thus the trend of all our experience is the same.
Now there are some certainties which are only centres of concurrent probabilities; there are some truths determined only by succession of facts, but yet, by their intersection and convergence, sufficiently determined.
"That is how we measure the distance from an inaccessible point, by regarding it time after time from the points to which we have access." ("Report of the French Philosophical Society", meeting, 2nd May 1901.)
Is not that the case here? The affirmative seems all the more inevitable inasmuch as the language of transformism is the only language known to the biology of today. Evolution can, it is true, be transposed, but not suppressed, since in any actual state there would always remain this striking fact that the living forms met with as remains in geological layers are ranged by the natural affinity of their characteristics in an order of succession parallel to the succession of the ages. We are not really then inventing a hypothesis in beginning with the affirmation of evolution. But what we have to do is to appreciate its object.
Evolution! We meet the word everywhere today. But how rare is the true idea! Let us ask the astronomers who originate cosmogonical hypotheses, and invent a primitive nebula, the natural philosophers who dream that by the deterioration of energy and the dissipation of movement the material world will obtain final rest in the inertia of a homogeneous equilibrium, let us ask the biologists and psychologists who are enemies of fixed species and inquisitive about ancestral history. What they are anxious to discern in evolution is the persistent influence of an initial cause once given, the attraction of a fixed end, a collection of laws before the eternity of which change becomes negligible like an appearance. Now he who thinks of the universe as a construction of unchangeable relations denies by his method the evolution of which he speaks, since he transforms it into a calculable effect necessarily produced by a regulated play of generating conditions, since he implicitly admits the illusive character of a becoming which adds nothing to what is given.
Finality itself, if he keeps the name, does not save him from his error, for finality in his eyes is nothing but an efficient cause projected into the future. So we see him fixing stages, marking periods, inserting means, putting in milestones, continually destroying movement by halting it before his gaze. And we all do the same by instinctive inclination. Our concept of law, in its classical form, is not general: it represents only the law of co-existence and of mechanism, the static relation between two numerically disconnected terms; and in order to grasp evolution we shall doubtless have to invent a new type of law: law in duration, dynamic relation. For we can, and we must, conceive that there is an evolution of natural laws; that these laws never define anything but a momentary state of things; that they are in reality like streaks determined in the flux of becoming by the meeting of contrary currents. "Laws," says Monsieur Boutroux, "are the bed down which passes the torrent of facts; they have dug it, though they follow it." Yet we see the common theories of evolution appealing to the concepts of the present to describe the past, forcing them back to prehistoric times, and beyond the reasoning of today, placing at the beginning what is only conceivable in the mind of the contemporary thinker; in a word, imagining the same laws as always existing and always observed. This is the method which Mr Bergson so justly criticises in Spencer: that of reconstructing evolution with fragments of its product.