A Case Against Omniscience: Fallibility

FIFTH DRAFT FOR REVIEW (14 December 2022)

Many philosophers have given thought to the contradiction between God's omniscience and human beings' capacity to act freely. Other philosophers have written on the tensions between the notions of omniscience and knowledge itself. For example, Grim [1984, 2013: §§V–VII] argues that there is no set of all truths for God to know. Grim [1983: §§5–7, 1985, 2013: §§VIII–IX] and others [Wierenga 2021] also point out the problem of indexicals (How God cannot know what I know: that I am writing an essay, for example).

The concept of omniscience can be thought of as generating paradoxes akin to that generated by the concept of omnipotence. If an omnipotent being is all-powerful, can it create a stone it cannot lift? If it can create such a stone but not be able to lift it, it can't be omnipotent. On the other hand, if it can't create such a stone, it can't be omnipotent. Likewise, if an omniscient being knows all truths, does it know how to deceive itself while leaving no trace of deception? If it doesn't know how to deceive itself, then there is something it doesn't know and so can't be omniscient. If it does know how to deceive itself without a trace, then it can't know it is currently omniscient. Either way, it can't be omniscient.

This essay constitutes one of three arguments about the impossibility of omniscience. For this essay, I present a case based on what it is to know something as opposed to merely believing something that is true. My other two arguments [Allan 2022b] are independent of the one presented here and draw attention to how knowing everything leads to an infinite regress.

In this essay, I will proceed as follows. First, I will present two informal versions of the argument that I hope illustrates its intuitive plausibility and is comprehensible by readers not versed in formal logic. Next, I will present the argument formally in standard English in a way that captures the formal logical structure of the argument. My final presentation of the argument will be in symbolic form using first order predicate logic. The aim here is to elucidate the logical structure of the argument with its formal entailments as rigorously as possible. In the final sections of this essay, I will address a variety of basic objections that can be dispensed with quickly before considering four more sophisticated counter-arguments.

Copyright © 2022 Leslie Allan