This is the second of six talks on the social and political philosophy of Saint Thomas Aquinas, presented by the Catholic and Dominican Institute of Mount Saint Mary College this June, at the Sixth Annual Philosophy Workshop. It follows on the heels of the first lecture by Professor Steven Long elaborating on the idea of the common good. In this second lecture, Fr. Dominic Legge, OP turns to discuss Aquinas on justice and human law, and its relation to the common good. This lecture is an excellent introduction to these themes from a Thomistic perspective, as well as highlighting the difference between it and so-called social contract theories of justice and law, among others.