Classical Theism and Pantheism: a Victory for Process Theism?

In Anselm's Discovery, Professor Hartshorne makes the rather startling and (I think) counterintuitive claim that ‘…there is indeed no issue between theism and pantheism. We all exist in the divine being, as St Paul said.’1 Classical or orthodox theists, it seems eminently fair to say, can be expected to recoil from any such suggestion with more than a little indignation. First of all, it might well be objected that Hartshorne - as a ‘process theist’ (or, as he often calls himself, a ‘neoclassical theist’) - is not a classical theist, and, consequently, while there may be no issue between pantheism and his brand of theism, such is simply not the case in so far as classical theism is concerned. According to the latter - in contradistinction, of course, to Hartshorne's ‘neoclassical theism’ - immutability is an ‘essential’ property of God; as such, it would be a conceptual error to ascribe any contingent (i.e. changeable) states to God at all. Now as is well known by philosophers of religion, Hartshorne regards this immutability doctrine of classical theism as a serious ‘logical blunder’ (loc. cit.), one which - in so far as it reflects the ‘Greek bias’ which has always (but mistakenly) identified perfection with the absolutely unchangeable - is profoundly distortive of the biblical concept of Deity.