— 559 —
      §29. In some of our Ideas there are certain Relations, Habitudes,
and Connexions, so visibly included in the Nature of the Ideas
themselves, that we cannot conceive them separable from them, by
any Power whatsoever. And in these only, we are capable of certain
and universal Knowledge. Thus the Idea of a right-lined Triangle
necessarily carries with it an equality of its Angles to two right
ones. Nor can we conceive this Relation, this connexion of these
two Ideas, to be possibly mutable, or to depend on any arbitrary
Power, which of choice made it thus, or could make it otherwise.
But the coherence and continuity of the parts of Matter; the pro-
duction of Sensation in us of Colours and Sounds, etc. by impulse
— 560 —
and motion; nay, the original Rules and Communication of Motion
being such, wherein we can discover no natural connexion with any
Ideas we have, we cannot but ascribe them to the arbitrary Will
and good Pleasure of the Wise Architect. I need not, I think, here
mention the Resurrection of the dead, the future state of this
Globe of Earth, and such other Things, which are by every one
acknowledged to depend wholly on the Determination of a free
Agent. The Things that, as far as our Observation reaches, we
constantly find to proceed regularly, we may conclude, do act by a
Law set them; but yet by a Law, that we know not: whereby,
though Causes work steadily, and Effects constantly flow from
them, yet their Connexions and Dependancies being not discoverable
in our Ideas, we can have but an experimental Knowledge of them.
From all which ’tis easy to perceive, what a darkness we are
involved in, how little ’tis of Being, and the things that are, that
we are capable to know. And therefore we shall do no injury to our
Knowledge when we modestly think with our selves, that we are
so far from being able to comprehend the whole nature of the Uni-
verse, and all the things contained in it, that we are not capable of
a philosophical Knowledge of the Bodies that are about us, and make
a part of us: Concerning their secondary Qualities, Powers, and
Operations, we can have no universal certainty. Several effects come
every day within the notice of our Senses, of which we have so far
sensitive Knowledge: but the causes, manner, and certainty of their
production, for the two foregoing Reasons, we must be content
to be ignorant of. In these we can go no farther than particular
Experience informs us of matter of fact, and by Analogy to guess
what Effects the like Bodies are, upon other tryals, like to produce.
But as to a perfect Science of natural Bodies, (not to mention
spiritual Beings,) we are, I think, so far from being capable of any
such thing, that I conclude it lost labour to seek after it.
Locke Hum IV, 3, §29, pp. 559-560