Classical scholars have, I believe, a general principle, difficilior lectio potior—the more difficult reading is to be preferred—in textual criticism. If the Archbishop of Canterbury tells one man that he believes in God, and another that he does not, then it is probably the second assertion which is true, since otherwise it is very difficult to understand why he should have made it, while there are many excellent reasons for his making the first whether it be true or false.
G. H. Hardy, Ramanujan: Twelve Lectures on Subjects Suggested by His Life and Work, Cambridge, 1940, p. 4