“In scholastic discussions on causality, one more cause is brought up to add to the four already mentioned. This is the instrumental cause (*causa instrumentalis*). The *causa instrumentalis* could be described as the subordinate efficient cause (*causa efficiens*). In Reformed theology, God is in many respects the *causa efficiens* of all that takes place in reality. Thus, in His providence God is the *causa efficiens* of all that happens in the world. God is also the efficient cause of the Holy Scriptures. In particular, however, God is the efficient cause of human salvation and also the *causa efficiens* of justification and faith. Yet, Reformed Scholasticism constantly insists that a person does not remain merely passive in these divine works and that God involves humanity as *causa instrumentalis*. Thus it was the human authors themselves who wrote and preserved the Scriptures as God’s instruments. It is also man himself who accepts the justification effected by God with a believing heart.
(T. Theo J. Pleizier and Maarten Wisse, “‘As the Philosopher Says’: Aristotle,” in Willem J. van Asselt ed. *Introduction to Reformed Scholasticism* (RHB 2011), p. 40.)