reasoning, perhaps, one may deny to be founded on the relation of cause
and effect. I shall not dispute about a word. It will be sufficient to
observe that our assurance in any argument of this kind is derived from
no other principle than our observation of the veracity of human
testimony, and of the usual conformity of facts to the reports of
witnesses. It being a general maxim, that no objects have any
discoverable connexion together, and that all the inferences, which we
can draw from one to another, are founded merely on our experience of
their constant and regular conjunction; it is evident, that we ought not
to make an exception to this maxim in favour of human testimony, whose
connexion with any event seems, in itself, as little necessary as any
other. Were not the memory tenacious to a certain degree, had not men
commonly an inclination to truth and a principle of probity; were they
not sensible to shame, when detected in a falsehood: Were not these, I
say, discovered by experience to be qualities, inherent in human nature,
we should never repose the least confidence in human testimony. A man
delirious, or noted for falsehood and villany, has no manner of
authority with us.

And as the evidence, derived from witnesses and human testimony, is
founded on past experience, so it varies with the experience, and is
regarded either as a _proof_ or a _probability_, according as the
conjunction between any particular kind of report and any kind of object
has been found to be constant or variable. There are a number of
circumstances to be taken into consideration in all judgements of this
kind; and the ultimate standard, by which we determine all disputes,
that may arise concerning them, is always derived from experience and
observation. Where this experience is not entirely uniform on any side,
it is attended with an unavoidable contrariety in our judgements, and
with the same opposition and mutual destruction of argument as in every