Various, Encyclopaedia Britannica, 11th Edition…
“ This principle involved the paradox that no man, knowing good, would do evil. But it was a paradox derived from his unanswerable truisms, “Every one wishes for his own good, and would get it if he could,” and “No one would deny that justice and virtue generally are goods, and of all goods the best.” All virtues are, therefore, summed up in knowledge of the good. But this good is not, for Socrates, duty as distinct from interest. The force of the paradox depends upon a blending of duty and interest in the single notion of good, a blending which was dominant in the common thought of the age. ”
