 The composed and eclectic character of the whole is even more evident in the three other sections. In the second section, the Epistles 15–22 follow the Hellenistic arrangement of Aristotle's works on physics. Epistle 15 echoes the themes addressed in the Physics. In Epistle 16, entitled, On the heaven and the world, the Ikhwân are shown to be in line with the Muslim tradition which transformed the ancient De caelo into a new book De caelo et mundo. Epistle 17 deals with De generatione and corruptione. Epistle 18 about meteorological phenomena and Epistle 19 about minerals recall the contents of Meteorology I-III and IV respectively. Meteor. IV, sometimes considered spurious and “the first chemical work in ancient world” according to scholars, was the basis of the theories of “chemical” or “alchemical” transformations in Islamic sciences and of mineralogy. The Ikhwanian treatise deals with mineralogy, geology and gemmology and in the correspondence established between the celestial and sub-lunar worlds, between the stars and minerals, it expresses one of the main tenets of alchemy. Further Aristotelian echoes are found in Epistle 24 On sense and sensation, to which Epistle 35 On intellect and intelligible corresponds in the third section. After topics concerning nature, such as the human body in Epistle 23, conception in Epistle 25, and man as microcosm in Epistle 26 [on the relationship between micro- an macrocosm see Maukola, 2009 and, in quite a new perspective, Nokso-Koivisto, 2011) the most important topic for the Ikhwân, the human spiritual dimension is addressed. It is discussed in terms of the relationship between soul and body in Epistles 27 e 28, life and death in Epistle 29, and pleasures in Epistle 30. The Aristotelian theory of the immovable mover, which is introduced in Epistle 37 On love, to explain the movement imparted to stars by the heavenly Universal Soul accomplishes its religious meaning. It serves to confirm the love human beings feel for permanence and their hatred for death: God is the most beloved as the everlasting cause of all beings.