en rejected, it is liable to this
unanswerable objection, so long as space is assumed to have an
_objective_ existence, viz. that the human inability to conceive such
a possibility, only argues (what in fact is often found in other
cases) that the _objective_ existence of space--_i. e._ the existence
of space in itself, and in its absolute nature--is far larger than its
subjective existence--_i. e._ than its mode of existing _quoad_ some
particular subject. A being more limited than man might be so framed
as to be unable to conceive curve lines; but this subjective
inaptitude for those determinations of space would not affect the
objective reality of curves, or even their subjective reality for a
higher intelligence. Thus, on the hypothesis of an objective existence
for space, we should be thrown upon an ocean of possibilities, without
a test for saying what was--what was not possible. But, on the other
hypothesis, having always in the last resort what is _subjectively_
possible or impossible (_i. e._ what is conceivable or not by us, what
can or cannot be drawn or circumscribed by a human imagination), we
have the means of demonstration in our power, by having the ultimate
appeals in our power to a known uniform test--viz. a known human
faculty.

This is no trifling matter, and therefore no trifling advantage on the
side of Kant and his philosophy, to all who are acquainted with the
disagreeable controversies of late years among French geometricians of
the first rank, and sometimes among British ones, on the question of
mathematical evidence. Legendre and Professor Leslie took part in one
such a dispute; and the temper in which it was managed was worthy of
admiration, as contrasted with the angry controversies of elder days,
if, indeed, it did not err in an opposite spirit, by too elaborate and
too calculating a tone of reciprocal flattery. But think as we may of
the discussion in this respect, most assuredly it was painful to
witness so infirm a philosophy applied to an interest so mighty. The
whole aerial superstructure--the heaven-aspiring pyramid of
geometrical synthesis--all tottered under the palsying logic of
evidence, to which these celebrated mathematicians appealed. And
wherefore?--From the want of any philosophic account of space, to
which they might have made a common appeal, and which might have so
far discharged its debt to truth, as at least to reconcile its theory
with the great outstanding phenomena i