t nothing certain, nothing entirely satisfactory can be reached. The
failure of the great writers whose works we have been contemplating may
well teach us humility, make us distrust ourselves, and moderate within
us any sanguine hopes of success. But they should not make us wholly
despair of at least showing in what direction the solution of the
difficulty is to be sought, and whereabouts it will probably be found
situated, when our feeble reason shall be strengthened and expanded.
For one cause of their discomfiture certainly has been their aiming too
high, attempting a complete solution of a problem which only admitted of
approximation, and discussion of limits.

It is admitted on all hands that the demonstration is complete which
shows the existence of intelligence and design in the universe. The
structure of the eye and ear in exact confirmity to the laws of optics
and acoustics, shows as clearly as any experiment can show anything,
that the source, cause or origin is common both to the properties of
light and the formation of the lenses and retina in the eye--both to the
properties of sound and the tympanum, malleus, incus and stapes of the
ear. No doubt whatever can exist upon the subject, any more than, if
we saw a particular order issued to a body of men to perform certain
uncommon evolutions, and afterwards saw the same body performing those
same evolutions, we could doubt their having received the order. A
designing and intelligent and skillful author of these admirably adapted
works is equally a clear inference from the same facts. We can no more
doubt it than we can question, when we see a mill grinding corn into
flour, that the machinery was made by some one who designed by means of
it to prepare the materials of bread. The same conclusions are drawn
in a vast variety of other instances, both with respect to the parts
of human and other bodies, and with respect to most of the other
arrangements of nature. Similar conclusions are also drawn from our
consciousness, and the knowledge which it gives us of the structure of
the mind.[3] Thus we find that attention quickens memory and enables us
to recollect; and that habit renders all exertions and all acquisitions
easy, beside having the effect of alleviating pain.

But when we carry our survey into other parts, whether of the natural
or moral system, we cannot discover any design at all. We frequently
perceive structures the use of which we know nothing about;