degree of assurance in the testimony of witnesses, gives us also, in
this case, another degree of assurance against the fact, which they
endeavour to establish; from which contradition there necessarily arises
a counterpoize, and mutual destruction of belief and authority.

_I should not believe such a story were it told me by Cato_, was a
proverbial saying in Rome, even during the lifetime of that
philosophical patriot.[20] The incredibility of a fact, it was allowed,
might invalidate so great an authority.

[20] Plutarch, in vita Catonis.

The Indian prince, who refused to believe the first relations concerning
the effects of frost, reasoned justly; and it naturally required very
strong testimony to engage his assent to facts, that arose from a state
of nature, with which he was unacquainted, and which bore so little
analogy to those events, of which he had had constant and uniform
experience. Though they were not contrary to his experience, they were
not conformable to it.[21]

[21] No Indian, it is evident, could have experience that water
did not freeze in cold climates. This is placing nature in a
situation quite unknown to him; and it is impossible for him to
tell _a priori _what will result from it. It is making a new
experiment, the consequence of which is always uncertain. One
may sometimes conjecture from analogy what will follow; but
still this is but conjecture. And it must be confessed, that,
in the present case of freezing, the event follows contrary to
the rules of analogy, and is such as a rational Indian would
not look for. The operations of cold upon water are not