ABSTRACT
One well-known argument for divine immutability, of Aristotelian inspiration, argues from the impossibility of self-motion to the existence of an unmoved prime mover of all physical processes. 1 I gave Aquinas’s version of the argument in chapter 1 above. Scotus is hesitant about arguments of this nature: ‘if perhaps they are valid, they nevertheless have a restricted conclusion’. 2 The reason is that Scotus believes self-motion to be a widespread feature of the physical universe; 3 at best, then, Aristotle’s arguments could show that ‘the first mover does not move as a body does, or as an embodied power, as the soul is moved accidentally in moved body’. 4 Scotus believes, however, that it is an easy matter to demonstrate God’s immutability from his simplicity:
[1 ]
Because God is perfectly simple (as was proved from his infinity), he cannot be
changed to some form which is received in him; because he is necessary existence (as
was proved from the primacy of efficiency …), he cannot be changed from existence
to non-existence, or from non-existence to existence. … God is said therefore to be
simply immutable in every [kind of] mutation, substantial or accidental. 5
