the uncertain light of the sense,
sometimes shining out, sometimes clouded over, through the woods
of experience and particulars; while those who offer themselves for
guides are (as was said) themselves also puzzled, and increase the
number of errors and wanderers. In circumstances so difficult neither
the natural force of man's judgment nor even any accidental felicity
offers any chance of success. No excellence of wit, no repetition of
chance experiments, can overcome such difficulties as these. Our
steps must be guided by a clue, and the whole way from the very first
perception of the senses must be laid out upon a sure plan. Not that I
would be understood to mean that nothing whatever has been done in so
many ages by so great labours. We have no reason to be ashamed of the
discoveries which have been made, and no doubt the ancients proved
themselves in everything that turns on wit and abstract meditation,
wonderful men. But as in former ages when men sailed only by
observation of the stars, they could indeed coast along the shores
of the old continent or cross a few small and mediterranean seas; but
before the ocean could be traversed and the new world discovered, the
use of the mariner's needle, as a more faithful and certain guide,
had to be found out; in like manner the discoveries which have been
hitherto made in the arts and sciences are such as might be made by
practice, meditation, observation, argumentation,--for they lay near
to the senses, and immediately beneath common notions; but before we
can reach the remoter and more hidden parts of nature, it is necessary
that a more perfect use and application of the human mind and
intellect be introduced.

For my own part at least, in obedience to the everlasting love of
truth, I have committed myself to the uncertainties and difficulties
and solitudes of the ways, and relying on the divine assistance have
upheld my mind both against the shocks and embattled ranks of opinion,
and against my own private and inward hesitations and scruples, and
against the fogs and clouds of nature, and the phantoms flitting about
on every side; in the hope of providing at last for the present and
future generations guidance more faithful and secure. Wherein if I
have made any progress, the way has been opened to me by no other
means than the true and legitimate humiliation of the human spirit.
For all those who before me have applied themselves to the invention
of arts have but c