
Two Precepts of Charity (1273)
Sermons on the Ten Commandments (Collationes in decem praeceptes, c. 1273), Prologue (opening sentence)
Variant translation: Three things are necessary for the salvation of man: to know what he ought to believe; to know what he ought to desire; and to know what he ought to do.
Original: (la) Tria sunt homini necessaria ad salutem: scilicit scientia credendorum, scientia desiderandorum, et scientia operandorum.