It seems to be intuitively true that in order to know a posteriori knowledge, we must experience it or have empirical evidence for it. To use Thomas Nagel’s classic example, in order to know what it is like to be a bat, one must experience it firsthand. Thus, according to what is called concept empiricism, one’s knowledge of sensations and emotions (such as lust and envy) is contingent on their having experienced them. If this is true, then it would seem that God, being omniscient, must know lust and envy and thus must have experienced it. However this contradicts the very nature of God, and hence it is argued that God is necessarily non-existent. Michael Martin structures the argument as:
- If God exists, God has not had the feelings of lust or envy.
- If God exists, God exists as a being who knows at least everything man knows.
- If God exists as a being who knows at least everything man knows, God knows lust and envy.
- If God knows lust and envy, God has had the feelings of lust and envy.
- God exists.
- .: God has had and has not had the feelings of lust and envy.
- God does not exist.
Theists may respond to this argument in several different ways. Some assert that God only have propositional and not experiential knowledge. Others maintain that God can know feelings of lust and envy, yet in a way which does not compromise God’s necessary goodness. The problem with the first solution seems obvious. If God’s knowledge is only propositional and not experiential, then in addition to not knowing feelings of lust or envy, God cannot also know feelings of love or mercy! Though it eliminates the problem, the solution itself would compromise several key tenets of God’s nature because there is no logical stopping point. Thus, the theist cannot accept the first solution.
While it is indeed true in regards to contingent beings such as ourselves that we cannot know sensations or emotions without experiencing them, there is no reason why it should be true in regards to God. It would only be true in regards to God if it were a necessary truth. But there is nothing about concept empiricism which makes it necessary. ”Even if human beings cannot grasp x without experiencing x, is this a self-evident principle that governs all possible forms of knowing?”
One can certainly conceive of a possible world in which they know what it is like to swim because a demented neurosurgen implanted the memory in their mind. Moreover, there could exist a possible world in which I do know what it is like to fly a plane, but in which I imagine doing so, and that imagination is enough to justify my knowing what it is like to fly a plane. Or perhaps there could exist a possible world in which I do not know what it is like to ride a roller coaster, but in which that experience was directly generated and implanted into me. Being omnipotent, God could come to know what it is like to lust, envy, swim, fly, and ride a roller coaster without having to actually experience these things, as he could simply could just directly generate the event or imagine it.
The theist can also argue that God’s experiential knowledge is perhaps known in the same way as his propositional knowledge.
Everyone agrees that God need not acquire certain forms of knowledge that humans must acquire. For example, I have to study long and hard to master the Calculus. But God, if He exists, knows all mathematical truths eternally and essentially in virtue of His omniscience; He never has to learn mathematics. Maybe God’s knowledge by acquaintance, then, is like His mathematical knowledge: He does not acquire it, but simply has it.
There thus are many possible ways in which God could know experiential knowledge in a way in which he does not need to experience it to know it. In order to be binding on God, concept empiricism would have to be necessarily true. But again, there is no reason to suppose this. There is no contradiction in asserting that God could know experiential knowledge by directly generating it, imagining it, or knowing it in the same way he does propositional knowledge. There are a wide range of possibilities to which God could thus know experiential knowledge. It seems questionable in the first place to generalize in such a way.