This paper looks at the causal activity of the unmoved mover of Aristotle. The author affirms both the efficient causality of God and his teleological role. According to Aristotle, the main explanation, by describing God, is ‘thinking on thinking’. That means his most important factor to act cannot only ‘be aimed’ but must also ‘be thought’. The final causality is based on the higher energeia what owns the efficient cause, since the energeia itself is regarded by Aristotle as good. God as unmoved mover not moves as a form such the idea of the Good, but as individual and active substance. The goal of the divine activity is God himself, while the other immaterial substances move the spheres as instruments for the change in the world. Insofar those substances are intelligent agents, they are ends for themselves and for their effects. Many new texts to defend such as an efficient causal interpretation are quoted.