If this reasoning has been refuted I do not know by whom. The astonishing fact is that it was not refuted but ignored or dogmatically dismissed by every important later theologian and philosopher who was presented in standard histories of philosophy or encyclopedias down to the present century. To this very day one cannot find the Socinian view of the partial mutability of God referred to in standard reference works. I regard this as a revealing instance of how false it is that the basic possibilities for speculative philosophy and theology have been exhausted long ago by the well-known figures reported upon in the histories and compendia of knowledge. The French movement called existentialism rests essentially upon this false supposition, as one can see by reading Sartre or Camus. They call existence 'absurd,' largely on the ground that there is no escape from the dilemma: either omnipotent divine power settles everything and so is responsible for every evil as well as every good and we human beings have no genuine freedom, or we have freedom and there is no God, at least none worth worshipping. It is precisely the Socinian God that is worth worshipping, and that is the one most scholars know nothing about.
Charles Hartshorne, Whitehead's View of Reality, 15-16
Basically the Socinians said, according to Hartshorne, that perfect knowledge is defined as knowing everything there is to know. God as omniscient would mean that God knows everything there is to know. This in conjunction with their view of human freedom makes the doctrine that humans can affect God and God can affect humans. Humans, by simply choosing x over y contribute to God's knowledge of the actual world. Thus, God's knowledge about the world changes. Thus God too changes. This is the dipolar nature of God: that though God has a necessary character he too has an unnecessary or inessential aspect. For example, my experience of a fan at this moment isn't necessary for me to exist. It is an accidental aspect of existence, although now that I am experiencing the fan it does affect me.
