 Al-Fārābī, Avicenna and Averroes share the view that happiness is reached through the conjunction of the human intellect with the separate active intellect. They also share an epistemological optimism that for specifically gifted people, which they described as philosophers or philosopher-prophets, a perfect conjunction is possible in this life. Albertus Magnus’s theory of happiness is much influenced by these Arabic theories. As was mentioned above, he adopted from Avicenna and Averroes the concept of an “acquired intellect” (intellectus adeptus) as the highest level of conjunction between possible and active intellect. Only in this stage, a human being truly becomes a human being. Through the conjunction with the active intellect the human intellect contemplates the separate substances, and in this consists the “theoretical happiness” of man (felicitas contemplativa), a happiness which is possible in this life (De anima III.3.12) (Müller 2006; on Albertus’ influence see de Libera 2005, 329–361). Thomas Aquinas disagrees with the epistemological premisses and the ethical conclusion of this position: Since human knowledge is bound to the senses, knowledge of the immaterial substances is not possible in this life, and neither is perfect human happiness (Summa theol. Ia IIae q.3 a.2). But Thomas, when explaining beatific vision and human happiness in the afterlife, adopts from Averroes the idea that a separate substance is conjoined with the human intellect as its form (Comm. on the Sentences IV, d.49 q.2 a.1; see Taylor 2012)