— 532 —
Not without precedent doubt.
      §5. Another difference between intuitive and demonstrative knowledge,
is, that though in the latter all doubt be removed, when by the
— 533 —
Intervention of the intermediate Ideas, the Agreement or Dis-
agreement is perceived; yet before the Demonstration there was a
doubt, which in intuitive Knowledge cannot happen to the Mind
that has its Faculty of Perception left to a degree capable of distinct
Ideas, no more than it can be a doubt to the Eye, (that can distinctly
see White and Black,) Whether this Ink, and this Paper be all of a
Colour. If there be Sight in the Eyes, it will at first glimpse, without
Hesitation, perceive the Words printed on this Paper, different
from the Colour of the Paper: And so if the Mind have the Faculty
of distinct Perception, it will perceive the Agreement or Disagree-
ment of those Ideas that produce intuitive Knowledge. If the Eyes
have lost the Faculty of seeing, or the Mind of perceiving, we in
vain enquire after the quickness of Sight in one, or clearness of
Perception in the other.
Locke Hum IV, 2, §5, pp. 532-533