and varied pictures passing before them, experience the feeling that
there no longer exist systems fixed in an immobility which seems that
of death. They feel that nothing is unchangeable; that ceaseless
transformations are taking place before their eyes; and that this
continuous evolution and perpetual change are the necessary conditions
of progress.

A great number of seekers, moreover, show themselves on their own
account perfectly eclectic. They adopt, according to their needs, such
or such a manner of looking at nature, and do not hesitate to utilize
very different images when they appear to them useful and convenient.
And, without doubt, they are not wrong, since these images are only
symbols convenient for language. They allow facts to be grouped and
associated, but only present a fairly distant resemblance with the
objective reality. Hence it is not forbidden to multiply and to modify
them according to circumstances. The really essential thing is to
have, as a guide through the unknown, a map which certainly does not
claim to represent all the aspects of nature, but which, having been
drawn up according to predetermined rules, allows us to follow an
ascertained road in the eternal journey towards the truth.

Among the provisional theories which are thus willingly constructed by
scholars on their journey, like edifices hastily run up to receive an
unforeseen harvest, some still appear very bold and very singular.
Abandoning the search after mechanical models for all electrical
phenomena, certain physicists reverse, so to speak, the conditions of
the problem, and ask themselves whether, instead of giving a
mechanical interpretation to electricity, they may not, on the
contrary, give an electrical interpretation to the phenomena of matter
and motion, and thus merge mechanics itself in electricity. One thus