I wasn’t making that up. I even marked a passage to share:
That public virtue which among the ancients was denominated patriotism, is derived from a strong sense of our own interest in the preservation and prosperity of the free government of which we are members. Such a sentiment, which had rendered the legions of the republic almost invincible, could make but a very feeble impression on the mercenary servants of a despotic prince; and it became necessary to supply that defect by other motives, of a different, but not less forcible nature; honour and religion.
from Gibbon’s The Decline and Fall of the Roman Empire, Moses Hadas (abridger), Fawcett Publications, Greenwich, Conn 1962 (page 27).