Summa contra Gentiles2.19 Chapter XIX. That in creation there is no succession

It is also clear from the foregoing that all creation is without succession.

For succession is proper to movement: while creation is not a movement nor the term of a movement, as change is. Therefore there is no succession therein.

Again. In every successive movement there is some mean between its extremes: for a mean is that which a continuously moved thing reaches first before reaching the term. Now between being and non-being which are as the extremes of creation, no mean is possible. Therefore there is no succession therein.

Moreover. In every making wherein there is succession, a thing is becoming before it has been made, as is proved in 6 Phys. Now this cannot happen in creation. Because the becoming which would precede being made, would need a subject. And this could not be the creature itself whose creation is in question, since it is not before it is made. Nor would it be in the maker, because to be moved is the act not of the mover, but of the thing moved. It follows that becoming would have for its subject some pre-existing matter of the thing made. But this is incompatible with creation. Therefore there can be no succession in creation.

Further. Every making that proceeds by succession must needs take time: since before and after in movement are reckoned by time. Now time, movement, and the thing subject to movement are all simultaneously divided. This is evident in local movement: for that which is moved with regularity passes through half a magnitude in half the time. Now the division in forms that corresponds to division of time is according to intensity and remissness: thus if a thing is heated to such a degree in so much time, it is heated to a less degree in less time. Accordingly succession in any movement or making is possible according as the thing in respect of which there is motion is divisible: either according to quantity, as in local movement and increase; or according to intensity and remission, as in alteration. Now the latter occurs in two ways. First, because the form which is the term of movement is divisible in respect of intensity and remission, as when a thing is in motion towards whiteness; secondly, because such a division happens in dispositions to such a form; thus the becoming of fire is successive on account of the previous alteration as regards the dispositions to the form. But the substantial being itself of a creature is not divisible in this way, for substance cannot be more or less. Nor do any dispositions precede creation, since there is no pre-existing matter, for disposition is on the part of matter. It follows therefore that there cannot be succession in creation.

Further. Succession in the making of things results from a defect of the matter, that is not suitably disposed rom the beginning for the reception of the form: where- 'ore, when the matter is already perfectly disposed for the form, it receives it in an instant. For this reason, since a diaphanous body is always in the last disposition for light, it is actually illumined as soon as the luminous body is present: nor does any movement precede on the part of the illuminable body, but only local movement on the part of the illuminant, which becomes present. But in creation nothing is required beforehand on the part of matter: nor does the agent lack anything for His action, that may afterwards accrue to Him through movement, since He is utterly immovable, as we have shown in the First Book of this Work. It follows therefore that creation is instantaneous. Hence in the same instant a thing is being created and is created, just as in the same instant a thing is being illumined and is illumined.

Hence divine Scripture declares that the creation of things took place in an indivisible instant, when it says: In the beginning God created heaven and earth: which beginning Basil expounds as the beginning of time, and this must be indivisible as is proved in 6 Phys