Elements of the philosophy of the human mind. By Dugald Stewart. Rev. and abridged, with critical and explanatory notes, for the use of colleges and schools. By Francis Bowen ...

4G2 REASONING AND DEDUCTIVE EVIDENCE.
to be impossible. Such conclusions, therefore, differ essentially
from those to which we are led by the demonstrations of pure
mathematics, which not only command our assent to the theorems they establish, but satisfy us that the contrary suppositions
are absurd.
These examples may suffice to convey a general idea of the
distinction between demonstrative and probable evidence; and
I purposely borrowed them from sciences where the two are
brought into immediate contrast with each other, and where the
authority of both has hitherto been equally undisputed.
Before prosecuting any further the subject of probable evidence, some attention seems to be due, in the first place, to the
grounds of that fundamental supposition on which it proceeds, -
the stability of the order of nature. Of this important subject, accordingly, I propose to treat at some length.
2. Of the permanence or stability in the order of nature,
which is presupposed in our reasonings concerning contingent
truths.- In the language of modern science, the established
order in the succession of physical events, is commonly referred
(by a sort of figure or metaphor) to the general laws of
natture. It is a mode of speaking extremely convenient fiom
its conciseness, but is apt to suggest to the fancy a groundless,
and, indeed, absurd analogy between the material and the
moral worlds. As the order of society results from the laws
prescribed by the legislator, so the order of the universe is
conceived to result from certain laws established by the Deity.
Thus, it is customary to say, that the fall of heavy bodies towards the earth's surface, the ebbing and flowing of the sea,
and the motions of the planets in their orbits, are consequences
of the law of gravitation. But although, in one sense, this
may be abundantly accurate, it ought always to be kept in
view, that it is not a literal, but a metaphorical, statement of the
truth; a statement somewhat analogous to that poetical expression in the sacred writings, in which God is said "to have
given his decree to the seas, that they should not. pass his com.: [See -ote to page 6.J