Both God and the human authors are efficient causes.
An efficient cause is an agent which brings about some effect.
Furthermore these are said to have emanated from God, who is both their formal and efficient cause.
This means that He acts as both a final and efficient cause.
Thus only efficient cause is what would now be called causation.
Aristotle held that there are basically four causes in nature: the efficient cause, the matter, the end, and the form.
Hence: The chief or most powerful motive; the efficient cause of action.
The only active power (hence the only efficient cause of change in the world) is God.
Brahman is the material and efficient cause of the universe.
The efficient cause is that external thing that causes the change in the first place.