St. Thomas Aquinas, Summa Theologica, Secunda Secundae, Q. 29, Art. 3, reply to ob. 3: “Peace is the ‘work of justice’ indirectly, in so far as justice removes the obstacles to peace: but it is the work of charity directly, since charity, according to its very nature, causes peace. For love is ‘a unitive force’ as Dionysius says (Div. Nom. iv): and peace is the union of the appetite’s inclinations.”