or
liberates energy--just as coal liberates energy when burned in the
engine. In both cases energy (contained in the food or the coal, as the
case may be) is liberated, and this energy is utilized to drive our
engine--the human body or the steam-engine (it makes no difference to
the argument). The energy thus gained is, it is contended, again given
off as heat and work--muscular and mental work in the case of the human
engine (the body); mechanical work of all sorts, and heat, in the case
of the steam-engine. Thus one is essentially no more mysterious than the
other--the body no more so than the steam-engine--vitality no more so
than steam! Both are "physical" energies, subject to the law of
conservation, and as such transmutable one into the other. This is the
generally accepted theory, which likens the human body to a
steam-engine, and is the theory all but universally adopted by
scientific men, held as proved and adopted without question by M.
Bergson!

But such a view of the case is, I believe, essentially untrue. It is
_one_ interpretation of the observed facts, truly; but not the only
interpretation. The facts remain equally true on either theory; the
difference lies in their explanation. It is the old error of confusing
coincidence with causation--and not only that, but a particular _kind_
of causation, and "treating it as the only imaginable kind." Just as the
psychologists reasoned upon the acknowledged facts of the relation of
brain and consciousness; so do the physiologists, in our own day, reason
upon this question of the causation of vital energy by food. In both
cases there has been one-sided and partial reasoning.

If, however, we reject the prevalent notion of the causation of vital
energy by food, we must have another theory to offer in its place. It
is, I know, presumptuous thus to run counter to the whole of accepted
teaching, in this respect, and my excuse must be that I believe my
theory represents the truth, while that universally held does not!
Again, I must emphasize that I speak, not of facts, but of inferences
drawn from facts. With this apology, I shall state my own view of the
case as follows:

Instead of comparing the human body with the steam-engine, it should be
compared with and likened to the _electric motor_. Just as the motor is
recharged, or receives its energy from some external source, just so, I
believe, is the human nervous system recharged from without, during the
hours of s