find [1]afterwards, that there is one very memorable exception, which is of vast consequence in the present subject of the understanding.
Mean while to give a solution of the preceding objection upon the supposition, that historical evidence amounts at first to an entire proof; let us consider, that tho' the links are innumerable, that connect any original fact with the present impression, which is the foundation of belief; yet they are all of the same kind, and depend on the fidelity of Printers and Copists. One edition passes into another, and that into a third, and so on, till we come to that volume we peruse at present. There is no variation in the steps. After we know one, we know all of them; and after we have made one, we can have no scruple as to the rest. This circumstance alone preserves the evidence of history, and will perpetuate the memory of the present age to the latest posterity. If all the long chain of causes and effects, which connect any past event with any volume of history, were compos'd of parts different from each other, and which 'twere necessary for the mind distinctly to conceive, 'tis impossible we shou'd preserve to the end any belief or evidence. But as most of these proofs are perfectly resembling, the mind runs easily along them, jumps from one part to another with facility, and forms but a confus'd and general notion of each link. By this means a long chain of argument, has as little effect in diminishing the original vivacity, as a much shorter wou'd have, if compos'd of parts, which were different from each other, and of which each requir'd a distinct consideration.
A fourth unphilosophical species of probability is that deriv'd from general rules, which we rashly form to ourselves, and which are the source of what we properly call Prejudice. An Irishman cannot have wit, and a Frenchman cannot have solidity; for which reason, tho' the conversation of the former in any instance be visibly very agreeable, and of the
- ↑ Part IV. sect. 1.
