[1] This section of the entry paraphrases (with slight variations) a Stoic doxography on physics: see Diogenes Laertius 7.132-133 (web address 1) and Hicks (236-239). The immediate source then becomes John Philoponus, Commentary on Aristotle's de anima 55.26-29, 55.31-57.7; cf. Hayduck in CAG XV.
[2] See Aristotle's distinction of the different sciences in Metaphysics 6.1. In this passage three of the methods of investigation are at least mentioned: physics, mathematics, and the first philosophy. Aristotle calls them 'sciences' or 'forms of knowledge' (epistemai; Met. 1025b18ff.), but to some extent they are also 'methods of investigation' (methodoi) in a specific field of research. Mathematics, physics and the first philosophy are included within what Aristotle calls 'theoretical sciences'. This passage is taken from John Philoponus, Commentary on Aristotle’s de anima 55.26-29; cf. van der Eijk (73). Philoponus here comments on Aristotle, de anima 403a29.
[3] Aristotle in fact first presents dialectically the views of previous philosophers and then argues for his own thesis.
[4] That is, the ether (see Aristotle, de caelo 1.2-3). To account for the change in the domain of the sphere under the moon Aristotle posits four elements (fire, air, water, earth), whose movements are toward their 'proper or natural' place: for fire and air, upwards, for water and earth, downwards. Thus all the bodies and natural magnitudes, Aristotle says, move by themselves according to place, for nature is for them the principle of movement (de caelo 268b14ff.). Since Aristotle thinks that the natural bodies are composed of these terrestrial four elements, their natural movement will be the 'proper movement' of the predominant element, that is, that element which is present in the object in a higher degree (see Physics 212b29-213a10; de caelo 301a20-302a9). By contrast, the heavenly bodies are just composed of ether, 'the fifth element', whose only movement is the circular one. The celestial bodies composed of this element undergo neither generation nor destruction (for the Aristotelian arguments in favor of this thesis, see de caelo 1).
[5] This passage follows Philoponus, op. cit., 55.31-56.4.
[6] Plato, Timaeus 38c-40c.
[7] Aristotle, de caelo 286b10ff. This portion of the entry is abstracted from Philoponus, op. cit., 56.4-20.
[8] Philoponus names Plotinus, not Plato as the lexicographer transmits.
[9] Plotinus 2.2.1.1. Here the entry follows Philoponus, op. cit., 56.21-26; cf. van der Eijk (73-74).
[10] Plotinus 5.1.7 reads: a)ll' ou) nou=s e)kei=no. pw=s ou)=n nou=n genna=|; h)\ o(/ti th=| e)pistrofh=| pro\s au(to\ e(w/ra. h( de\ o(/rasis au(/th nou=s. This could be translated as "But Intellect is not that [sc. Good]. How then does it generate Intellect? Because by its return to itself it sees, and this seeing is Intellect." This rendering conforms to Philoponus's interpretation as something inclining toward itself: to\ pro\s e(auto\n neu/ein. Despite the rough breathing in the Loeb text, Armstrong interprets (32-35) the Plotinean passage as not reflexive and as signaling an abrupt change of subject: "Because by its return to it it sees, and this seeing is Intellect".
[11] See Aristotle, de caelo 285a32, 286b10, 286b18-25, 291b11.
[12] The entry follows, with some paraphrasing, Philoponus, op. cit., 56.26-57.8; cf. van der Eijk (74). The Suda abruptly concludes the entry. Philoponus, however, goes on (57.8-15) to explain that, whereas the craftsman offers only proximate causes, the natural philosopher will explain the primary causes and provide both the matter and the form pertinent to the causal account.