(Latin: evolvere, to unfold)
Any process of nature by which a rudimentary condition develops into a more highly organized result, as a seed into a plant.
In a more specific sense, and as now commonly understood, evolution denotes the general and particular theories professing to account for cosmic processes of orderly change over a long period of time.
EVOLUTION AS A SCIENCE
(1) Cosmogony (kosmos, universe; gignomai, become), theories about the formation of the universe in general; as the development of the present heavenly bodies out of a previous nebular condition.
In particular, for the formation of our planetary system there is the theory elaborated by Chamberlain and Moulton (and subsequently by Jeans), according to which the planets and their motion are the result of a near encounter between the original mass of the sun and another large heavenly body which has long since passed on its way.
(2) Geogony (geos, earth; gignomai, become), theories concerning the processes which have brought the earth to its present condition.
Abundant data for thier study are furnished by the sciences of geology, geophysics and seismology.
For this reason, and also because many processes indicated in the earth's strata are observable as still going on, geogony is on a better footing than any other branch of evolutionary science.
In general, modern cosmogonies, based as they are on well-known laws, have met a friendly reception with Catholic philosophers.
Saint Thomas even forecast the discovery of the Copernican system, and held that "The earth was formerly in a potential state, its parts diffused".
Has to do with organisms, i.e., living bodies.
The scientific theories are not concerned with the origin of life itself but take organic life as a datum; nor are they concerned with the growth of individual organisms but witli the development of successive species of animals and plants from other species known to have existed in previous geological ages.
Every such theory favors mutability as opposed to the fixity of species.
In ancient times Hesiod, Anaximander, the Pythagoreans, Stoics, and others held mutability, while Plato and Aristotle argued for substantial fixity.
In modern times, to mention but a few names, Vanini (1586-1619) taught the descent of man from the ape, and Buffon (1707-1788) held that the primitive stocks were few.
These men were opposed by Linne (1707-1778) and Cuvier (1769-1832).
Lamarck (1744-1829) maintained that organic species are only relatively stable, so that certain groups of species may be but branches of the same genealogical tree.
Darwin (1809-1892), accepting the tenet of slight variations and that of progressive betterment, thought he found the secret of the latter in natural selection.
But neither Darwin's key to progress nor any other formula for evolutionary processes is now widely accepted by scientists.
"Lamarckism and Darwinism are now insufficient," says Maurice Caullery, "we do not know at present what have been the essential factors of evolution" (, 1920).
Likewise Bateson confesses that "When students of other sciences ask us what is now currently believed about the origin of species we have no clear answer to give.
We cannot see how the differentiation of species came about" (Evolutionary Faith and Modern Doubts, , LV, 55).
The same absence of any convincing theory to account for evolution is stressed by Osborn ().
In forming a judgment about evolution it is necessary to distinguish between fact and hypothesis.
It is a fact that the geological record reveals a succession of species with the simpler forms occurring as a rule earlier than the more highly organized.
The statement that the latter developed out of the former under the influence of purely natural agencies is hypothesis.
In support of this hypothesis we have such phenomena as the closely allied species of marine faunw on opposite sides of the Isthmus of Panama, and many other variant forms of life which diverge in proportion to the time at which their habitats were separated.
The strength of the hypothesis lies in the absence of any other plausible explanation, and in certain ob- served changes, as in the case of the Basset sheep, the evening primrose, and the Drosophila or fruit flies.
But such variations are quite limited.
If the hypothesis be extended to include genera, familics, etc., it is totally without confirmation except by specious arguments from comparative anatomy and embryology which largely suppose what they are meant to prove.
In spite of this many writers accept widespread evolution as a fact and so represent it to the public (, edited by Frances Mason).
The attitude of Catholics is the truly scientific one of being friendly to reasonable hypotheses and interested in their confirmation, while, like Pasteur, refusing to accept appearances as proofs.
There is not a shadow of proof for the generation of life from non-life, nor of animal from vegetal life, nor of the human organism from lower animals.
Hence reason must conclude that the Creator intervened at least at each of these stages.
With regard to the human soul Catholic philosophers hold on purely natural grounds, independently of religion and revelation, that the rational soul cannot be generated even by the human parents, but must be directly created.
Hence man as such is outside the possibility of evolution.
EVOLUTION AS A PHILOSOPHY
Supposes that the world is the only being extant and has evolved itself into all its stages of perfection including the human soul.
Such monistic philosophy is certainly opposed to religion which requires an adequate distinction between Creator and creature.
Many proponents of this philosophy pretend that their only opponent is revealed religion, whereas in all honesty both unbiased reason and impartial science are implacable foes of monistic evolution.
New Catholic Dictionary