5. See Daniel ii. 31-40. "And the fourth kingdom shall be
strong as 'iron'; for as much as iron breaketh in pieces and
subdueth all things." The remainder of the prophecy (the
mixture of iron and 'clay') was accomplished, according to
St. Jerom, in his own time. Sicut enim in principio nihil
Romano Imperio fortius et durius, ita in fine rerum nihil
imbecillius: quum et in bellis civilibus et adversus
diversas nationes, aliarum gentium barbararum auxilio
indigemus (Opera, tom. v. p. 572).