X. The first thing that offers itself to our consideration, is the little
or no progress, which natural reason, unassisted by experience, has made
in the examination of the affairs of nature in the course of so many
ages. Nature is as little understood in the schools at this day, as it
was in the academies of Plato, of Lyceus, and of Aristotle. What secret
have these academies developed? or what diminutive portion of this most
extensive country have they discovered? What utility has the labours of
so many men of excellent ingenuity, as have cultivated philosophy in the
reasoning and speculative way, produced to the world? What art, either
liberal or mechanical, of the many that are necessary for the service
of man, or the good of the public, do we owe to speculative invention;
and I might even say, what small advancement in any such art, has been
derived from it? What document of the schools, has conduced to instruct
a husbandman in the cultivation of his lands? They there talk much of
causes, effects, productions, and dispositions of matter, but all this
has not yet produced any maxim that can be relied on, for the most
advantageous mode of cultivating the land, in order to dispose it to the
production of this or that particular plant, nor to instruct us at what
time it should be sown, nor in the least to inform us with regard to
many other circumstances, that should be attended to in the raising it.
Schoolmen, after the example of Aristotle, treat largely of qualities,
which they place in a predicament apart, or by themselves; without having
by this means, discovered any qualities at all, either in the mixtures,
or the elements; but on the contrary, Aristotle has rather been miserably
mistaken in those he attempted to point out, by his rules of proportion
and combination; I mean in those that appertain to the air, and the
water, as we have proved in another part of our works; and it would
not be difficult to prove the same thing, with regard to those he has
assigned to the earth. If perchance he has been right in ascertaining
the qualities belonging to fire, (although in our _Physical Paradoxes_
we have denied his position with respect to its being hot in the highest
degree) I say, if he has been right in this particular, it was not
because philosophy had penetrated the secret, but because the thing was
manifested to us by our senses.
XI. These are the organs, by which all the natural truths we are
able to obtain a knowledge of are conveyed to our spirits. Even in
the mathematical faculties, which affect to confide every thing to
theoretical demonstrations, they cannot, except in the two elemental
ones, arithmetic and geometry, safely advance a step, without
holding before them, the light of experience. It was this taught the
geographer, the situation and position of the divers parts of the globe;
the navigator, the directive virtue of the load-stone; the static
philosopher, the weight, the descent, and acceleration of motion in their
descent, of heavy bodies; the mechanic and engineer, the augmentation of
power by machinery, or the multiplication of purchase; the astronomer,
the movements and course of the stars; the musician, the consonant and
dissonant intervals of music; the optician, perspective, or the effects
of vision when the eye surveys distant objects; to the catoptrician, and
dioptrician, the laws of reflexion, and refraction.