Seite - 25 - in The Priority of Locomotion in Aristotle’s Physics

2.3 The eight books of the Physics 2.3.1 Physics I–IV: Examining change for the sake of understanding nature The Physics as it has come down to us basically needs to be considered as a work that develops the fundamental principles which govern the natural world and with which the student of nature has to be acquainted in order to carry out more specific inquiries.40 In Physics II Aristotle, therefore, raises the question what nature (φύσις), the principle of natural things (τὰ φύσει ὀντά) is. Nature, Aristotle tells us, is a source of change (ἀρχὴ κινήσεως) and rest inside the thing that has this nature.41 For instance all living beings, but also the elemental bodies like earth, water, fire, and air, contain the principle of change within them- selves.42 Since nature is explained by referring to change, the student of nat- ure has to grasp what change (and rest) is in order to understand what nat- ure is.43 Accordingly, Aristotle develops a definition of change, but also points out that several other terms need to be examined that are commonly thought necessary for understanding what change is. For this reason the remainder of Book III and the whole of Book IV discuss the concepts of the infinite (ἄπειρον), place (τόπος), void (κενόν), and time (χρόνος).44 This is consistent with the fact that the first four books of the Physics originally formed an independent treatise On Nature that dealt with nature and its principles. Again, the student of nature needs to deal with change in order to under- stand what nature is. Therefore, at first glance it might look as though Books V–VIII also continue the task of inquiring into the phenomenon of change in order to understand nature as a principle of change and rest, since we find a thorough examination of change in the four remaining books of the Physics. Yet, it is most likely that Aristotle thought differently. This can be seen from the fact that he points out that first (πρῶτον) one 40 Wagner (1967), 287, thinks that the Physics need to be understood as a “Naturlehre” that is fundamental to the other more specific areas. Also Wieland (1992), 18–19, states that the Physics in no way deals with specific natural things, but only with the general principles of natural things and for this reason may even be called a metaphysical inquiry. Morison (2002), 1–2, finally argues that the Physics accordingly need to be considered as a philosophi- cal inquiry that however is “in part using empirical data” (1). 41 See Phys. II 1, 192b13–23, and Phys. III 1, 200a12–13. 42 See Phys. II 1, 192b9–13. 43 See Phys. III 1, 200a12–15. 44 Aristotle lays out this plan in Phys. III 1, 200b12–25. The infinite is discussed in III 4– 8, place in IV 1–5, the void in IV 6–9, and time in IV 10–14. The eight books of the Physics 25 ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen