Aristotle: Thing (page 3)

“But it is better to assume principles less in number and finite, as Empedocles makes them to be. All philosophers… make principles to be contraries… (for Parmenides makes principles to be hot and cold, and these he demominates fire and earth) as those who introduce as principles the rare and the dense. But Democritus makes the principles to be the solid and the void; of which the former, he says, has the relation of being, and the latter of non-being. …it is necessary that principles should be neither produced from each other, nor from other things; and that from these all things should be generated. But these requisites are inherent in the first contraries: for, because they are first, they are not from other things; and because they are contraries, they are not from each other.”

Aristotle book Physics

Book I, Ch. VI, pp. 53-55.
Physics

“Since the science of nature is conversant with magnitudes, motion, and time, each of which must necessarily be either infinite or finite…[we] should speculate the infinite, and consider whether it is or not; and if it is what it is. …[A]ll those who appear to have touched on a philosophy of this kind… consider it as a certain principle of beings. Some, indeed, as the Pythagoreans and Plato, consider it, per se, not as being an accident to any thing else, but as having an essential subsistence… the Pythagoreans… consider the infinite as subsisting in sensibles; for they do not make number to be separate; and they assert that what is beyond the heavens is infinite; but Plato says that beyond the heavens there is not any body, nor ideas, because these are no where: he affirms, however, that the infinite is both in sensibles, and in ideas. …Plato establishes two infinities, viz. the great and the small.”

Aristotle book Physics

Book III, Ch. IV, pp. 150-152.
Physics

Idea , Nature , Appearance , Science

“The natural way of doing this [seeking scientific knowledge or explanation of fact] is to start from the things which are more knowable and obvious to us and proceed towards those which are clearer and more knowable by nature; for the same things are not 'knowable relatively to us' and 'knowable' without qualification. So in the present inquiry we must follow this method and advance from what is more obscure by nature, but clearer to us, towards what is more clear and more knowable by nature. Now what is to us plain and obvious at first is rather confused masses, the elements and principles of which became known to us by later analysis…”

Aristotle book Physics

A.1, 184a.16 sqq, source: http://classics.mit.edu//Aristotle/physics.html, Book I, Part 1, Tr. R. P. Hardie, R. K. Gaye.
Physics

Way , Nature , Knowledge

“It is impossible for the same attribute at once to belong and not to belong to the same thing and in the same relation"; and we must add any further qualifications that may be necessary to meet logical objections. This is the most certain of principles, since it possesses the required definition; for it is impossible for anyone to suppose that the same thing is and is not, as some imagine that Heraclitus says.”

Aristotle book Metaphysics

Book IV, 1005
Metaphysics
Original: (el) τὸ γὰρ αὐτὸ ἅμα ὑπάρχειν τε καὶ μὴ ὑπάρχειν ἀδύνατον τῷ αὐτῷ καὶ κατὰ τὸ αὐτό （καὶ ὅσα ἄλλα προσδιορισαίμεθ᾽ ἄν, ἔστω προσδιωρισμένα πρὸς τὰς λογικὰς δυσχερείας）: αὕτη δὴ πασῶν ἐστὶ βεβαιοτάτη τῶν ἀρχῶν: ἔχει γὰρ τὸν εἰρημένον διορισμόν. ἀδύνατον γὰρ ὁντινοῦν ταὐτὸν ὑπολαμβάνειν εἶναι καὶ μὴ εἶναι, καθάπερ τινὲς οἴονται λέγειν Ἡράκλειτον.
Source: https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0051%3Abook%3D4%3Asection%3D1005b

Imagination

“If, then, in the sphere of action there is some one end which we desire for its own sake, and for the sake of which we desire every thing else; and if we do not choose every thing for the sake of something else, for this would go on without limit, and our desire would be idle and futile, it is clear that this must be the supreme good, and the best thing of all.”

Aristotle

Bk I, Ch I
The Ethics Of Aristotle (Vol. I)

“Every art, and every system, and in like manner every action and purpose aims, it is thought, at some good; for which reason a common and by no means a bad description of the good is, ‘that at which all things aim.’”

Aristotle

Bk I, Ch I
The Ethics Of Aristotle (Vol. I)

Art