fluence over our judgments
is no less predetermining than that of the original categories. Hence
we reason by the ETERNAL and ABSOLUTE laws of our mind, and at the same
time by the secondary rules, ordinarily faulty, which are suggested to
us by imperfect observation. This is the most fecund source of false
prejudices, and the permanent and often invincible cause of a multitude
of errors. The bias resulting from these prejudices is so strong that
often, even when we are fighting against a principle which our mind
thinks false, which is repugnant to our reason, and which our conscience
disapproves, we defend it without knowing it, we reason in accordance
with it, and we obey it while attacking it. Enclosed within a circle,
our mind revolves about itself, until a new observation, creating within
us new ideas, brings to view an external principle which delivers us
from the phantom by which our imagination is possessed.

Thus, we know to-day that, by the laws of a universal magnetism whose
cause is still unknown, two bodies (no obstacle intervening) tend to
unite by an accelerated impelling force which we call GRAVITATION. It is
gravitation which causes unsupported bodies to fall to the ground, which
gives them weight, and which fastens us to the earth on which we live.
Ignorance of this cause was the sole obstacle which prevented the
ancients from believing in the antipodes. "Can you not see," said St.
Augustine after Lactantius, "that, if there were men under our feet,
their heads would point downward, and that they would fall into the
sky?" The bishop of Hippo, who thought the earth flat because it
appeared so to the eye, supposed in consequence that, if we should
connect by straight lines the zenith with the nadir in different places,
these lines would be parallel with each other; and in the direction
of these lines he traced every movement from above to below. Thence he
naturally concluded that the stars were rolling torches set in the vault
of the sky; that, if left to themselves, they would fall to the earth in
a shower of fire; that the earth was one vast plain, forming the lower
portion of the world, &c. If he had been asked by what the world itself
was sustained, he would have answered that he did not know, but that
to God nothing is impossible. Such were the ideas of St. Augustine in
regard to space and movement, ideas fixed within him by a prejudice
derived from an appearance, and which had become with him a gene