"the master of wisdom," they are not the true friends of
science, nor of the world's progress. "By far the greatest obstacle," says
Bacon, "to the advancement of the sciences, _is to be found in men's
despair and idea of impossibility_."

Even in the minds of those who cultivate a particular branch of knowledge,
there is often an internal secret despair of finding the truth, which so
far paralyzes their efforts as to prevent them from seeking it with that
deep earnestness, without which it is seldom found. The history of optics
furnishes a most impressive illustration of the justness of this remark.
Previous to the time of Newton, no one seemed to entertain a real hope
that this branch of knowledge would ever assume the form and clearness of
scientific truth. The laws and properties of so ethereal a substance as
light, appeared to elude the grasp of the human intellect; and hence, no
one evinced the boldness to grapple directly with them. The whole region
of optics was involved in mists, and those who gave their attention to
this department of knowledge, abandoned themselves, for the most part, to
vague generalities and loose conjectures. In the conflict of manifold
opinions, and the great variety of hypotheses which seemed to promise
nothing but endless disputes, the highest idea of the science of optics
that prevailed, was that of something in relation to light which might be
plausibly advanced and confidently maintained. It was reserved for Newton
to produce a revolution in the mode of treating this branch of knowledge,
as well as that of physical astronomy. Not despairing of the truth, he
sternly put away "innumerable fancies flitting on all sides around him,"
and by searching observation and experiment, brought his mind directly
into contact with things themselves, and held it steadily to them, until
the clear light of truth dawned. The consequence was, that the dreams of
philosophy, falsely so called, gave place to the clear realities of
nature. It was to the unconquerable hope, no less than to the profound
humility of Newton, that the world is indebted for his most splendid
discoveries, as well as for that perfect model of the true spirit of
philosophy, which combined the infinite caution of a Butler with the
unbounded boldness of a Leibnitz. The lowliest humility, free from the
least shadow of despair, united with the loftiest hope, without the least
mixture of presumption, both proceeding from an invincible love