  The first two criteria, Leslie explains, “make it impossible for any such matter of fact to be imposed upon men, at the time when such fact was said to be done, because every man’s eyes and senses would contradict it.” The latter two criteria assure those who come afterwards that the account of the event was not invented subsequent to the time of the purported event. Leslie points out that these criteria are not necessary conditions of factual truth, but he insists that they are—taken jointly—sufficient. Hence we may speak of Leslie’s principle: If any reported event meets all four of these criteria, then its historicity is certain.