the strongest impressions: Veraque constituunt, quæ bellè tangere possunt Aureis, et lepido quæ sunt fucata sonore. _Lucretius, lib. 1. l. 644._ A masterly painting has the same effect. Le Brun is no small support to Quintus Curtius; and among the vulgar in Italy, the belief of scripture-history is perhaps founded as much upon the authority of Raphael, Michael Angelo, and other celebrated painters, as upon that of the sacred writers[27]. In establishing the foregoing theory, the reader has had the fatigue of much dry reasoning. But his labour will not be fruitless. From this theory are derived many useful rules in criticism, which shall be mentioned in their proper places. One specimen, being a fine illustration, I chuse to give at present. In a historical poem representing human actions, it is a rule, that no improbable incident ought to be admitted. A circumstance, an incident, or an event, may be singular, may surprise by being unexpected, and yet be extremely natural. The improbability I talk of, is that of an irregular fact, contrary to the order and course of nature, and therefore unaccountable. A chain of imagined facts linked together according to the order of nature, find easy entrance into the mind; and if described with warmth of fancy, they produce complete images, including ideal presence. But it is with great difficulty that we admit any irregular fact; for an irregular fact always puzzles the judgement. Doubtful of its reality we immediately enter upon reflection, and discovering the cheat, lose all relish and concern. This is an unhappy effect; for thereafter it requires more than an ordinary effort, to restore the waking dream, and to make the reader conceive even the more probable incidents as passing in his presence.