To Florus 1.79

For the human being was made a rational, mortal living being, capable of virtue and vice. Through the capacity granted to him, he could either keep God's commands or transgress them, or by nature's teaching preserve the law of human fellowship. He was free to will either alternative; in this lies the substance of sin and justice. For when he draws something according to virtue for those in need, either from the springs of mercy or from the breasts of justice, it is justice itself working outwardly, which a holy will conceived and brought forth within.