PHIL 310 Aristotle's God: ‘The Un-moved Mover’/Pure Actuality/‘Best Thing’/Divine Mind

I. 'Substances are the primary reality, and if they are all perishable then everything is perishable. But motion cannot be either generated or destroyed, nor time…And there is no continuous motion except that which is spatial…and circular...Therefore the 'ultimate heaven' must be eternal. And since that which moves while itself moving is intermediate, there must be something which moves without being moved (Aristotle, Metaphysics 1071b-72a).

Cf. Aquinas (1225-1274), Summa Theologica I,2,3: 'Therefore, whatever is moved is moved by another. If that by which it is moved be itself moved then this also must needs be moved by another, and that by another again. But this cannot go on to infinity, because there would be no first mover, and consequently no other mover…Therefore it is necessary to arrive at a first mover moved by no other, and this everyone understands to be God.' [Aquinas’ 'First Way' or first proof of the existence of God]

II. '...for that which has potentiality may not actualize it. Thus it will not help if we postulate eternal substances…unless there be in them some principle which can cause change. And even this is not enough…for unless it actually functions there will not be motion. And it will still not be enough even if it does function, if its essence is potentiality, for there will not be eternal motion, since that which exists potentially may not exist. Therefore there must be a principle of this kind whose essence is actuality.’ (Aristotle, Metaphysics 1071b)

Cf. Aquinas, Summa Theologica I,2,3: 'We find in nature things that are possible to be and not to be...but it is impossible for these always to exist, for that which can not be at some time is not...Therefore not all things are merely possible, but there must exist something the existence of which is necessary...This all men speak of as God.' [Aquinas' 'Third Way'].

III. 'We must also consider in which sense the nature of the universe contains the good or supreme good; whether as something separate and independent, or as the orderly arrangement of its parts. Probably in both senses, as an army does; for the efficiency of the army consists partly in the order and partly in the general; but chiefly in the latter...all things, both fishes and birds and plants, are ordered together in some way...everything is ordered together in one way. (Aristotle, Metaphysics 1075a).

Cf. Aquinas, Summa Theologica I,2,3: 'We see things which lack knowledge, such as natural bodies, acting for an end, and this is evident from their acting always, or nearly always in the same way, so as to achieve the best result. Hence it is plain that they do achieve their ends not fortuitously, but designedly. Now whatever lacks knowledge cannot move towards an end unless it be directed by some being endowed with intelligence…Therefore some intelligent being exists by whom all natural things are directed to their end, and this being we call God.' [Aquinas' 'Fifth Way'].

IV.'But since there is something -X- which moves while being itself unmoved, existing actually, X cannot be otherwise in any respect...Thus X is necessarily existent; and qua necessary it is good, and in this sense is a first principle. For 'the necessary' has all these meanings [including] 'that without which excellence is impossible’… Such then is the first principle upon which depend the sensible universe and the world of nature. And its life is like the best that we can temporarily enjoy. But it must be in that state always.' (Aristotle, Metaphysics 1072b)

Aquinas, Summa Theologica I,2,3: 'Among beings things there are some more or less good, true, noble, and the like...so that there is something which is truest, something best, something noblest, and consequently something that is most being, for those things that are greatest in truth are greatest in being, as it is written in Metaph. ii [993b30]...Therefore there must be something which is to all beings the cause of their being, goodness, and every other perfection, and this we call God.' [Aquinas' 'Fourth Way'].

V ‘The divine mind, then, must think itself, and its thinking is a thinking of thinking’ (Aristotle, Metaphysics 1074b).