of relative significance, any comparison between the degree
of certainty attained by reasoning upon so transcendental a subject as the
present, and that of mathematical demonstrations regarding relative truth,
must be misleading. In the present instance, the whole strain of the
argument comes upon the adequacy of the proposed test of truth, viz., our
being able to conceive it if true. Now, will any one undertake to say that
this test of truth is of equivalent value when it is applied to a triangle
and when it is applied to the Deity. In the one case we are dealing with a
geometrical figure of an exceedingly simple type, with which our experience
is well acquainted, and presenting a very limited number of relations for
us to contemplate. In the other case we are endeavouring to deal with the
_summum genus_ of all mystery, with reference to which experience is quite
impossible, and which in its mention contains all the relations that are to
us unknown and unknowable. Here, then, is the oversight. Because men find
conceivability a valid test of truth in the affairs of everyday life--as it
is easy to show _a priori_ that it must be, if our experience has been
formed under a given code of constant and general laws--therefore they
conclude that it must be equally valid _wherever_ it is applied; forgetting
that its validity must perforce decrease in proportion to the distance at
which the test is applied from the sphere of experience.[8]

Sec. 16. Upon the whole, then, I think it is transparently obvious that the
mere fact of our being unable to conceive, say, how any disposition of
matter and motion could possibly give rise to a self-conscious
intelligence, in no wise warrants us in concluding that for this reason no
such disposition is possible. The only question would appear to be, whether
the test which is here proposed as an unconditional criterion of truth
should be allowed any the smallest degree of credit. Seeing, on the one
hand, how very fallible the test in question is known to have proved itself
in many cases of much less speculative difficulty--seeing, too, that even
now "the philosophy of the condition proves that things there are which
may, nay must, be true, of which nevertheless the mind is unable to
construe to itself the possibility;"[9] and seeing, on the other hand, that
the substance of Mind, whatever it is, must necessarily be
unknowable;--seeing these things, if any question remains as to whether the
test