dle and of rather puerile subtlety. They had seen the
ruin of most of the systems built up _a priori_ by daring
philosophers, and deemed it more prudent to listen to the advice given
by Kirchhoff and "to substitute the description of facts for a sham
explanation of nature."

It should however be remarked that these physicists somewhat deceived
themselves as to the value of their caution, and that the mistrust
they manifested towards philosophical speculations did not preclude
their admitting, unknown to themselves, certain axioms which they did
not discuss, but which are, properly speaking, metaphysical
conceptions. They were unconsciously speaking a language taught them
by their predecessors, of which they made no attempt to discover the
origin. It is thus that it was readily considered evident that physics
must necessarily some day re-enter the domain of mechanics, and thence
it was postulated that everything in nature is due to movement. We,
further, accepted the principles of the classical mechanics without
discussing their legitimacy.

This state of mind was, even of late years, that of the most
illustrious physicists. It is manifested, quite sincerely and without
the slightest reserve, in all the classical works devoted to physics.
Thus Verdet, an illustrious professor who has had the greatest and
most happy influence on the intellectual formation of a whole
generation of scholars, and whose works are even at the present day
very often consulted, wrote: "The true problem of the physicist is
always to reduce all phenomena to that which seems to us the simplest
and clearest, that is to say, to movement." In his celebrated course
of lectures at l'Ecole Polytechnique, Jamin likewise said: "Physics
will one day form a chapter of general mechanics;" and in the preface
to his excellent course of lectures on physics, M. Violle, in 1884,
thus expresses himself: "The science of nature tends towards mechanics
by a necessary evolution, the physicist being able to establish solid
theories only on the laws of movement." The same idea is again met
with in the words of Cornu in 1896: "The general tendency should be to
show how the facts observed and the phenomena measured, though first
brought together by empirical laws, end, by the impulse of successive
progressions, in coming under the general laws of rational mechanics;"
and the same physicist showed clearly that in his mind this connexion
of phenomena with mechanics had a d