Sobriety is the strength of the soul, for it preserves its reason unclouded by passion.
Notes from Wikiquote
Sobriety is the strength of the mind; for it preserves reason unclouded by passion. | As quoted in Bible of Reason (1831) by Benjamin F. Powell, p. 157 | Strength of mind rests in sobriety; for this keeps your reason unclouded by passion. | As quoted in Dictionary of Quotations from Ancient and Modern English and Foreign Sources (1899) by James Wood