"The superiority of Scientific Evidence Reexamined":

"Allow me now to ask, Will he be so perfectly satisfied on the first trial as not to think it of importance to make a second, perhaps u third, and a fourth? Whence arises this diffidence'! Purely from the consciousness of the fallibility of his own faculties. But to what purpose, it may be said, the reiterations of the at-tempt, since it is impossible for him, by any efforts, to shake off his dependence on the accuracy of his attention and fidelity of his memory? Or, what can he have more than reiterated testimonies of his memory, in support of the truth of its for-mer testimony? I acknowledge, that after a hundred attempts he can have no more. But even this is a great deal. We learn from experience, that the mistakes or oversights committed by the mind in one operation. arc sometime!-., on a review, corrected on the second, or perhaps on a third. Besides, the repetition, when no error is discovered, enlivens the remembrance, and so strengthens the conviction. But, for this conviction. it is plain that we are in a great measure indebted to memory. and in some measure even to experience." (Campbell 922)