2. What belongs to a thing by its nature, and is not dependent on any causation from without, cannot suffer diminution or defect. For if anything essential is withdrawn from or added to nature, that nature, so increased or diminished, will give place to another. If on the other hand the nature is left entire, and something else is found to have suffered diminution, it is clear that what has been so diminished does not absolutely depend on that nature, but on some other cause, by removal of which it is diminished. Whatever property therefore attaches to a thing less in one instance than in others, does not attach to that thing in mere virtue of its nature, but from the concurrence of some other cause. The cause of all effects in a particular kind will be that whereof the kind is predicated to the utmost. Thus we see that the hottest body is the cause of heat in all hot bodies, and the brightest body the cause of brightness in all bright bodies. But God is in the highest degree 'being' (B. I, Chap. XIII). He then is the cause of all things whereof 'being' is predicated.*
3. The order of causes must answer to the order of effects, since effects are proportionate to their causes. Hence, as special effects are traced to special causes, so any common feature of those special effects must be traced to some common cause. Thus, over and above the particular causes of this or that generation, the sun is the universal cause of all generation; and the king is the universal cause of government in his kingdom, over the officials of the kingdom, and also over the officials of individual cities. But being is common to all things. There must then be over all causes some Cause to whom it belongs to give being.
4. What is by essence, is the cause of all that is by participation, as fire is the cause of all things fiery, as such. But God is being by His essence because He is pure being; while every other being is being by participation, because there can only be one being that is its own existence (B. I, Chapp. XXII, XLII). God therefore is cause of being to all other beings.
5. Everything that is possible to be and not to be, has some cause: because, looked at by itself, it is indifferent either way; and thus there must be something else that determines it one way. Hence, as a process to infinity is impossible, there must be some necessary being that is cause of all things which are possible to be and not to be.*
6. God in His actuality and perfection includes the perfections of all things (B. I, Chap. XXVIII); and thus He is virtually all. He is therefore the apt producing cause of all.
This conclusion is confirmed by divine authority: for it is said: Who made heaven and earth, the sea, and all things that are therein (Ps. cxlv, 6). And, All things were made by him, and without him was made nothing (John ~, 3). And From whom are all things, by whom are all things, in (unto) whom are all things (Rom. xi, 16).
2.14 : That the Predication of many Relations of God is no prejudice to the Simplicity and Singleness of His Being
2.16 : That God has brought things into being out of nothing