3. Thirdly, Intuitive knowledge extends itself not to all the relations of all our ideas.
Thirdly, That we cannot have an
intuitive knowledge that shall extend itself to all our ideas, and all that we would know about them; because we
cannot examine and perceive all the relations they have one to another, by juxta-position, or an immediate
comparison one with another. Thus, having the ideas of an obtuse and an acute angled triangle, both drawn from
equal bases, and between parallels, I can, by intuitive knowledge, perceive the one not to be the other, but cannot
that way know whether they be equal or no; because their agreement or disagreement in equality can never be
perceived by an immediate comparing them: the difference of figure makes their parts incapable of an exact
immediate application; and therefore there is need of some intervening qualities to measure them by, which is
demonstration, or rational knowledge.