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The only impregnable citadel of virtue is religion; for there is no bulwark of mere morality, which some temptation may not overtop or undermine, and destroy.

Sir Philip Sidney, Jane Porter (1807). “Aphorisms of Sir Philip Sidney: With Remarks”, p.21
The only impregnable citadel of virtue is religion; for there is no bulwark of mere morality, which some temptation may not overtop or undermine, and destroy.