ONLY A THEORY?
Some reject the Darwinism by saying that it is "only a theory". This
argument has two weaknesses. Firstly, it ignores the fact that
Darwin affirmed two
things: that the modern species go down from ancestral forms and that the natural
selection is the principal mechanism of the evolution. The evolution is attested by
historical facts. To take no account of the data showing that the Mammals go
down from the Reptiles simply because nobody could observe the transition is
equivalent to denying the French Revolution under pretexte that none among us was
witness of it.
Then, what remains theoretical about the evolution? The theories
remain attempts of explanation, synthesis and integration of the facts. For the
biologists, the theory of evolution of Darwin bring back to the natural selection, the
mechanism that Darwin put in to explain the facts revealed by paleontology,
biogeography and the other historical disciplines.
Consequently, the argument "only a theory"
relates only to the second assertion of Darwin, the theory of the
natural selection. But here appears the second weakness of the matter. The theory
term does not have in the scientific field the same significance as in the current
language. In its familiar employment, the theory term has the significance
that the scientists give to the word hypothesis. In sciences, a theory
constitutes a statement more global than an hypothesis.
A theory, like the theory of the gravitation of Newton or that of the natural selection
of Darwin, gives an account of multiple facts and tries to explain a large variety of
phenomena. And a theorie is recognized in sciences only if the theory is
resisting repeated systematic checks in the form of experiments and observations.
Moreover, the good scientists do not let the theories set up in
dogmas. For example, of many biologists of evolution wonder today if only the natural
selection suffices to explain the history told by the geological files. The
study of evolution becomes more vigorous and more dynamics than ever. But
the fact of wondering about the mechanism of the evolution does not imply to considere
the evolution like "simple theory". We can compare the debate
on the theory of the evolution with the debate on the theories of the gravitation: the
objects fall and us, we discuss the causes of their fall.
Darvin has gave to biology a solid scientific base by allotting the diversity of the living to natural causes than to a supernatural intention. Despite everything, the variety and the harmony of the products of the evolution do not cease to fill us with wonder and to inspire us. As Darwin wrote in the last paragraph of the Origin of the species: "Is there not a true grandeur in this manner of considering the life?"