sive. Lichtenberg, indeed, showed that the very thing to be
proved was inevitably postulated in the first two words, 'I think;'
and it is plain that no inference from the postulate could, by any
possibility, be stronger than the postulate itself.

But Descartes deviated strangely from the idealism implied in his
fundamental principle. He was the first to reduce, in a manner
eminently capable of bearing the test of mental presentation, vital
phenomena to purely mechanical principles. Through fear or love,
Descartes was a good churchman; he accordingly rejected the notion of
an atom, because it was absurd to suppose that God, if He so pleased,
could not divide an atom; he puts in the place-of the atoms small
round particles, and light splinters, out of which he builds the
organism. He sketches with marvellous physical insight a machine,
with water for its motive power, which shall illustrate vital actions.
He has made clear to his mind that such a machine would be competent
to carry on the processes of digestion, nutrition, growth,
respiration, and the beating of the heart. It would be competent to
accept impressions from the external sense, to store them up in
imagination and memory, to go through the internal movements of the
appetites and passions, and the external movements of the limbs. He
deduces these functions of his machine from the mere arrangements of
its organs, as the movement of a clock, or other automaton, is deduced
from its weights and wheels. As far as these functions are
concerned,' he says, 'it is not necessary to conceive any other
vegetative or sensitive soul, nor any other principle of motion or of
life, than the blood and the spirits agitated by the fire which burns
continually in the heart, and which is in nowise different from the
fires existing in inanimate bodies.' Had Descartes been acquainted
with the steam-engine, he would have taken it, instead of a fall of
water, as his motive power. He would have shown the perfect analogy
which exists between the oxidation of the food in the body, and that
of the coal in the furnace. He would assuredly have anticipated Mayer
in calling the blood which the heart diffuses, 'the oil of the lamp of
life,' deducing all animal motions from the combustion of this oil, as
the motions of a steam-engine are deduced from the combustion of its
coal. As the matter stands, however, and considering the
circumstances of the time, the boldness, clearness, and pr