ed in given conditions into a certain quantity of motion. Still
further, our thought is now on the way toward resolving all these
physical factors into the flux of one universal energy, in which the
hypotheses of the atoms, in the extent to which it is necessary, loses
all residue of metaphysical survival.

Was it not inevitable, as a first step of knowledge in what concerns the
problem of life, to spend a considerable time in the separate study of
the organs and to reduce them to systems? Without this anatomy, which
seems too material and too gross, no progress in these studies would
have been possible; and nevertheless, above the unknown genesis and
co-ordination of such an analytic multiplicity, there were evolving,
uncertain and vague, the generic conceptions of life, soul, etc. In
these mental creations have long been seen that biological unity which
has finally found its object in the certain beginning of the cell and in
its _processus_ of immanent multiplication.

More difficult certainly was the way which the thought had to traverse
to reconstruct the genesis of all the facts of psychic life, from the
most elementary successions up to the most complex derived products. Not
only for reasons of theoretical difficulties, but in consequence of
popular prejudices, the unity and continuity of psychic phenomena
appeared, up to the time of Herbart, as separated and divided into so
many factors, faculties of the soul.

The interpretation of the historico-social _processus_ met the same
difficulties; it also was obliged to stop at first in the provisional
view of factors. And that being so, it is easy for us now to find again
the first origin of that opinion in the necessity that the historians
have of finding in the facts that they relate with more or less artistic
talent and in different professional views, certain points of immediate
orientation, such as may be offered by the study of the apparent
movement of human events.

But in this apparent movement, there are the elements of a more exact
view. These concurrent factors, which abstract thought conceives and
then isolates, have never been seen acting each for itself. On the
contrary, they act in such a manner that it gives birth to the concept
of reciprocal action. Moreover, these factors themselves arise at a
given moment, and it is not until later that they acquired that
physiognomy which they have in the particular narration. This State, it
is well known, ar