In His cooperating providence, God employs secondary causes (causae secundae), or means by which He preserves and directs the things which He has made. This is what we mean when we speak of divine concurrence. The relation of divine providence to such secondary means must be carefully noted; for in the divine act of concurrence both God works and the means (causae secundae) work. However, the operation of the means is not coordinate with that of God, but rather subordinate to it, so that the secondary causes work only so far and so long as God works through them, Ps. 127, 1. To emphasize this truth, our dogmaticians have said that the divine concurrence is not previous (actio praevia), but the operation of God and that of the means is numerically one (una numero actio). In other words, God concurs, but He does not precur; He cooperates, but does not "preoperate." "Concurrence is not antecedent, but occurs when the action itself is produced." (Hollaz.) Thus bread nourishes, medicine cures, water quenches thirst, etc., only because of God's continuous influence upon His creatures (Dei continuus in creaturas influxus). It is for this reason that God is called the First Cause (causa prima) and the creature the second cause (causa secunda), though the action of God and that of the creature is simultaneous. This is the Scriptural doctrine of divine concurrence, which is as much opposed to deism as it is to pantheism.
With respect to the laws of nature, Scripture teaches that they are not detached from the divine will, but are simply God's will exerted in the being and action of the creatures in order that they may be preserved both in their existence and operation. Scripture acknowledges no immutable laws of nature apart from the divine will; for while they may be immutable to feeble man, they are not immutable to the omnipresent God, who by His almighty power governs all things according to His will, Ps. 115, 3; 135, 6.