I was listening to a debate between George Williamson and William Lane Craig on the existence of God.  Williamson argued that the concept of God is incoherent.  He claimed omniscience would require that God possess all empirical knowledge (experiential, know-how), and yet God clearly does not know what it is like to play basketball, ride a bike, or sin.  Craig responded that the classical definition of omniscience holds that God knows all true propositions, not that He knows all experiences.  Williamson counters that theists have so defined omniscience only to escape the logical absurdities involved in a being who is truly omniscient.  So is the classical definition ad hoc as Williamson claims?  No.  There is good reason to limit omniscience to propositional knowledge.

If omniscience included empirical knowledge, then God could never create anything.  If He created an atom, He would have to have the experience of what it is like to be an atom.  Essential to the “experience” of being an atom is the lack of any conscious experience.  God, as a conscious being, cannot experience the lack of conscious experience (it’s a logical and metaphysical contradiction), and thus could not have the experience of being an atom.  Perhaps God could at least have the experience of being constituted by the physical entities that make up atoms: protons, neutrons, quarks, etc.  But then the atom would become a new way in which God exists.  Ultimately, we would end up with pantheism or monism, in which everything is God.

If omniscience included empirical knowledge, God could not even create other conscious beings, because omniscience would require that He have the experience of being that person.  But what makes a person a person is their unique consciousness.  If God had the experience of being the persons He created, then their consciousness would be God’s consciousness.  If their consciousness is indistinguishable from God’s consciousness, then there is in fact only one consciousness.  And if there is only one consciousness, then in reality there is only one person, not many.  For example, God could not create Napoleon Bonaparte because that would require both that Napoleon Bonaparte have the experience of being Napoleon Bonaparte, and God have the experience of being Napoleon Bonaparte.  Since two persons cannot have the experience of being a single person, God could not create other persons!

Requiring empirical knowledge of an omniscient being prohibits Him from being able to create other beings, and if God is unable to create other beings He is not omnipotent.  Knowledge of all empirical facts would be an imperfection, not a perfection.  There is, then, good reason for limiting omniscience to propositional knowledge.