thousand aspects under which
ignorance _supposes_ them to be.... To lay down at once the laws under
which society prospers or perishes, would be _virtually_ to destroy at
once all Sophisms. When Laplace described what, up to his time, was
known of the movements of celestial bodies, he dissipated, without even
naming them, all the astrological reveries of the Egyptians, Greeks, and
Hindoos, much more certainly than he could have done by attempting to
refute them directly, through innumerable volumes. Truth is one, and the
work which expounds it is an imposing and durable edifice. Error is
multiple, and of ephemereal nature. The work which combats it, cannot
bear in itself a principle of greatness or of durability.

But if power, and perhaps opportunity, have been wanting to me, to
enable me to proceed in the manner of Laplace and of Say, I still cannot
but believe that the mode adopted by me has also its modest usefulness.
It appears to me likewise to be well suited to the wants of the age, and
to the broken moments which it is now the habit to snatch for study.

A treatise has without doubt an incontestable superiority. But it
requires to be read, meditated, and understood. It addresses itself to
the select few. Its mission is first to fix attention, and then to
enlarge the circle of acquired knowledge.

A work which undertakes the refutation of vulgar prejudices, cannot have
so high an aim. It aspires only to clear the way for the steps of Truth;
to prepare the minds of men to receive her; to rectify public opinion,
and to snatch from unworthy hands dangerous weapons which they misuse.

It is above all, in social economy, that this hand-to-hand struggle,
this ever-reviving combat with popular errors, has a true practical
utility.

Sciences might be arranged in two categories. Those of the first class
whose application belongs only to particular professions, can be
understood only by the learned; but the most ignorant may profit by
their fruits. We may enjoy the comforts of a watch; we may be
transported by locomotives or steamboats, although knowing nothing of
mechanism and astronomy. We walk according to the laws of equilibrium,
while entirely ignorant of them.

But there are sciences whose influence upon the public is proportioned
only to the information of that public itself, and whose efficacy
consists not in the accumulated knowledge of some few learned heads, but
in that which has diffused itself into the