1911 Encyclopædia Britannica/Synderesis
SYNDERESIS, a term in scholastic philosophy applied to the inborn moral consciousness which distinguishes between good and evil. The word is really synteresis (Gr. συντήρησις, from συντηρεῖν, to look after, take care of), but synderesis is the commoner form. Diogenes Laërtius in his account of the Stoics (vii.85, τήν δὲ πρώτην ὁρµήν y 4ao-c TO TO TripeEv EaITO) uses the phrase TnpEiv EavrO to describe the instinct for self-preservation, the inward harmony of Chrysippus, the recognition of which is συνείδσις. The term synderesis, however, is not found till Jerome, who in dealing with Ezek. i. 4 -15, says the fourth of the "living creatures" of the vision is what the Greeks call συντήρησις, i.e. scintilla conscientiae the "spark of conscience." Here apparently synderesis and conscience (συνείδσις) are equivalent. By the schoolmen, however, the terms were differentiated, conscience being the practical envisaging of good and evil actions; synderesis being, so to speak, the tendency toward good in thought and action. The exact relation between the two was, however, a matter of controversy, Aquinas and Duns Scotus holding that both are practical reason, while Bonaventura narrows synderesis to the volitional tendency to good actions.