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. He thinks that the principal character, by describing God, is ‘thinking on thinking’. That means his most important factor to act cannot only ‘be aimed’ but must also ‘be thought’. There are many new texts to defend such as an efficient causal interpretation and also various philosophical arguments to support final causality.