If God is immutable, how is creation not a change in God?
Let us first consider what the immutability of God is:
Immutability of God
Absolute changelessness. That is mutable which goes from one condition to another. In consequence of its finite nature, every creature is mutable. God is unchangeable because he is infinite. Mutability implies potentiality, composition, and imperfection, and is therefore not reconcilable with God as pure actuality, the absolutely simple and infinitely perfect Being. When God acts outside of himself, as in the creation of the world, he does not produce a new effect in himself, but enters on a new realization of the eternal decision of his divine will. The decree of creation is as eternal and immutable as the Divine Essence with which it is really identical; only its effect, the created world, is temporal and changeable.
Thus we see that, even a simple definition of immutability declares that God is unchangeable. Yet he remains unchangeable in his act of creation, both of the physical universe and time although temporal and changeable remains outside of eternity, thus preserving his immutability intact.
Religious thinkers from Augustine through Thomas Aquinas, the major Christian philosophers argued that God was not in time at all. They thought of God as eternal, in the sense that he is timeless or atemporal.
Augustine connects God’s timeless eternity to God’s being the cause of all times and God’s immutability.
What times existed which were not brought into being by you? Or how could they pass if they never had existence? Since, therefore, you are the cause of all times, if any time existed before you made heaven and earth, how can anyone say that you abstained from working? (Augustine, Confessions, XI. xiii (15)).
It is not in time that you precede times. Otherwise you would not precede all times. In the sublimity of an eternity which is always in the present, you are before all things past and transcend all things future, because they are still to come. (Augustine, Confessions, XI. xiii (16)).
In you it is not one thing to be and another to live: the supreme degree of being and the supreme degree of life are one and the same thing. You are being in a supreme degree and are immutable. In you the present day has no ending, and yet in you it has its end: “all these things have their being in you” (Rom.11.36). They would have no way of passing away unless you set a limit to them. Because “your years do not fail” (Ps.101.28), your years are one Today. (Augustine, Confessions, I. vi (10))
Anselm (c. 1033–1109) presents a view similar to that of Boethius and Augustine.
Suppose, on the other hand, that it exists as a whole in individual times severally and distinctly. (A human being, for instance, exists as a whole yesterday, today and tomorrow.) In this case we should, properly, say that it was, is and will be. In which case its time-span is not simultaneously a whole. Rather it is stretched out in parts through the parts of time. But its time-span is its eternity and its eternity is precisely itself. The supreme essence, therefore, would be cut up into parts along the divisions of time. (Anselm, Monologion, Ch. 21)
For Anselm, the timeless eternity of God follows from God’s being that than which nothing greater can be conceived (cf. section 6.1). In the Proslogion, Anselm articulates a “grammar” of the divine powers, which determines what it makes sense to say of the most perfect being, including that being’s timelessness.
In the medieval period, the discussion embraces not only Christian but also Jewish and Islamic thinkers. In keeping with the sharp line drawn between the Creator and creation, Aquinas and the Jewish thinker Moses Maimonides (1131–1204) (who greatly influenced Aquinas) argue that God’s timeless eternity ought to be understood primarily in negative terms. For Aquinas, God’s timeless eternity is unending, lacking both beginning and end, and an instantaneous whole lacking succession. It is a correlate of divine simplicity (see the SEP entry on divine simplicity), and it is incapable of being defined or fully grasped by a creature. For Aquinas too, timeless eternity constitutes part of the “grammar” of talking about God. Since God is timelessly eternal it does not make any sense to ask how many years God has existed, or whether he is growing old, or what will he be doing later on in the year.
Despite differences with Thomas Aquinas regarding the nature of God’s relation to time, Duns Scotus (c.1266–1308) seems to have upheld divine timelessness (though see Leftow 1991: 228). In general, it would seem that commitment to divine simplicity, widespread if not universal in the medieval period, entails a commitment to divine timelessness (Mullins 2016: Ch. 3).
Eternity in Christian Thought
