and rejection lead to an inevitable conclusion. And
if that ordinary mode of judgment practised by the logicians was so
laborious, and found exercise for such great wits how much more labour
must we be prepared to bestow upon this other, which is extracted not
merely out of the depths of the mind, but out of the very bowels of
nature.

Nor is this all. For I also sink the foundations of the sciences
deeper and firmer; and I begin the inquiry nearer the source than men
have done heretofore; submitting to examination those things which
the common logic takes on trust. For first, the logicians borrow the
principles of each science from the science itself; secondly, they
hold in reverence the first notions of the mind; and lastly, they
receive as conclusive the immediate informations of the sense, when
well disposed. Now upon the first point, I hold that true logic
ought to enter the several provinces of science armed with a higher
authority than belongs to the principles of those sciences themselves,
and ought to call those putative principles to account until they
are fully established. Then with regard to the first notions of the
intellect; there is not one of the impressions taken by the intellect
when left to go its own way, but I hold it for suspected, and no
way established, until it has submitted to a new trial and a fresh
judgment has been thereupon pronounced. And lastly, the information
of the sense itself I sift and examine in many ways. For certain it
is that the senses deceive; but then at the same time they supply the
means of discovering their own errors; only the errors are here, the
means of discovery are to seek.

The sense fails in two ways. Sometimes it gives no information,
sometimes it gives false information. For first, there are very many
things which escape the sense, even when best disposed and no way
obstructed; by reason either of the subtlety of the whole body, or
the minuteness of the parts, or distance of place, or slowness or else
swiftness of motion, or familiarity of the object, or other causes.
And again when the sense does apprehend a thing its apprehension is
not much to be relied upon. For the testimony and information of the
sense has reference always to man, not to the universe; and it is a
great error to assert that the sense is the measure of things.

To meet these difficulties, I have sought on all sides diligently and
faithfully to provide helps for the sense--substitutes to