— 535 —
Why is has been so thought.
      §10. The Reason why it has been generally sought for, and
supposed to be only in those, I imagine, has been, not only the
general usefulness of those Sciences; But because, in comparing
their Equality or Excess, the Modes of Numbers have every the
least difference very clear and perceivable: and though in Extension,
every the least Excess is not so perceptible; yet the Mind has found
out ways, to examine and discover demonstratively the just
equality of two Angles, or Extensions, or Figures, and both these,
i.e. Numbers and Figures, can be set down, by visible and lasting
marks, wherein the Ideas under consideration are perfectly deter-
mined, which for the most part they are not, where they are
Locke Hum IV, 2, §10, p. 535