Walter Farrell's A Companion to the Summa
"Divine law leaves nothing unpunished that is contrary to virtue. Hence, according to the Divine law, it is reckoned unlawful if the equality of justice be not observed in buying and selling: and he who has received more than he ought must make compensation to him that has suffered loss, if the loss be considerable. I add this condition, because the just price of things is not fixed with mathematical precision, but depends on a kind of estimate, so that a slight addition or subtraction would not seem to destroy the equality of justice." S.T. II-II, Q77, A1, RO1
Sed lex divina nihil impunitum relinquit quod sit virtuti contrarium. Unde secundum divinam legem illicitum reputatur si in emptione et venditione non sit aequalitas iustitiae observata. Et tenetur ille qui plus habet recompensare ei qui damnificatus est, si sit notabile damnum. Quod ideo dico quia iustum pretium rerum quandoque non est punctaliter determinatum, sed magis in quadam aestimatione consistit, ita quod modica additio vel minutio non videtur tollere aequalitatem iustitiae.
Jacques Maritain's legacy in Canada
Jacques Maritain, "The End of Machiavellianism" in The Range of Reason
Jacques Maritain on St. Thomas Aquinas
Jacques Maritain on personalism
"The Political Commentary of Christopher Dawson and Jacques Maritain, 1927-1939"
"Nature and Grace: The Theological Foundations of Jacques Maritain's Public Philosophy"