Page:An Enquiry Concerning Human Understanding - Hume (1748).djvu/191

 stroy the Force of any Argument, deriv'd from human Testimony.

, for Instance, that the Fact, which the Testimony endeavours to establish, partakes of the Extraordinary and the Marvellous; in that Case, the Evidence, resulting from the Testimony, receives a Diminution, greater or less, in proportion as the Fact is more or less unusual. The Reason, why we place any Credit in Witnesses and Historians is not from any Connexion we perceive a priori betwixt Testimony and Reality, but because we are accustom'd to find a Conformity betwixt them. But when the Fact attested is such a one as has seldom fallen under our Observation, here is a Contest of two opposite Experiences; of which the one destroys the other as far as its Force goes, and the Superior can only operate on the Mind by the Force, which remains. The very same Principle of Experience, which gives us a certain 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 Contradiction there necessarily arises a Counterpoize, and mutual Destruction of Belief and Authority.

in order to increase the Probability against the Testimony of Witnesses, let us suppose, that the Fact,