reasoning, or any process of the understanding. This answer we must
endeavour both to explain and to defend.

29. It must certainly be allowed, that nature has kept us at a great
distance from all her secrets, and has afforded us only the knowledge of
a few superficial qualities of objects; while she conceals from us those
powers and principles on which the influence of those objects entirely
depends. Our senses inform us of the colour, weight, and consistence of
bread; but neither sense nor reason can ever inform us of those
qualities which fit it for the nourishment and support of a human body.
Sight or feeling conveys an idea of the actual motion of bodies; but as
to that wonderful force or power, which would carry on a moving body for
ever in a continued change of place, and which bodies never lose but by
communicating it to others; of this we cannot form the most distant
conception. But notwithstanding this ignorance of natural powers[6] and
principles, we always presume, when we see like sensible qualities, that
they have like secret powers, and expect that effects, similar to those
which we have experienced, will follow from them. If a body of like
colour and consistence with that bread, which we have formerly eat, be
presented to us, we make no scruple of repeating the experiment, and
foresee, with certainty, like nourishment and support. Now this is a
process of the mind or thought, of which I would willingly know the
foundation. It is allowed on all hands that there is no known connexion
between the sensible qualities and the secret powers; and consequently,
that the mind is not led to form such a conclusion concerning their
constant and regular conjunction, by anything which it knows of their
nature. As to past _Experience_, it can be allowed to give _direct_ and
_certain_ information of those precise objects only, and that precise
period of time, which fell under its cognizance: but why this experience
should be extended to future times, and to other objects, which for