This book is inspired by the quest for the proper function of Aristotle’s active intellect presented in De Anima 3.5. The urge to grasp its essence has always driven philosophy ahead. Nevertheless, the true nature of nous poietikos remains far from being grasped. I will not unravel it here either, I am afraid. My aim is far more modest: to get through the existing interpretations and try to systematise them somehow. To speak in a more poetic, metaphorical way: my aim is to sh...