As tys to saye Jacke! robys on.
Halliwell: Archæological Dictionary. (Cited from an old Play.)
Begging the question.
This is a common logical fallacy, petitio principii; and the first explanation of the phrase is to be found in Aristotle's "Topica," viii. 13, where the five ways of begging the question are set forth. The earliest English work in which the expression is found is "The Arte of Logike plainlie set forth in our English Tongue, &c." (1584.)
Better to wear out than to rust out.
When a friend told Bishop Cumberland (1632-1718) he would wear himself out by his incessant application, "It is better," replied the Bishop, "to wear out than to rust out."—Horne: Sermon on the Duty of Contending for the Truth.
Boswell: Tour to the Hebrides, p. 18, note.
Beware of a man of one book.
When St. Thomas Aquinas was asked in what manner a man might best become learned, he answered, "By reading one book." The homo unius libri is indeed proverbially formidable to all conversational figurantes.—Southey: The Doctor, p. 164.
Bitter end.