Wednesday, November 13, 2019


The following account of the doctrine of propositional omniscience is incomplete:

  1. x is omniscient iff x knows every truth and believes no falsehood.

For suppose that x believes no falsehood and knows every truth but is suffering from retrieval problems for the truths that x believes, in such a way that it takes x a minute to recall what is the capital of China. That’s not omniscience—it’s not sufficiently perfect as knowledge. This suggests to me that omniscience requires occurrent knowledge of every truth: a total contemplation of all of reality.

Moreover, suppose x knows every truth but some of these truths x is not sure of. Again, that’s not omniscience. Nor would it be omniscience if x were sure of every truth and believed no falsehood, but there was some falsehood to which x assigned a small degree of belief—say, a credence of 0.2. (For one, such a being would have probabilistically inconsistent credences, as it would assign credence 1 to the negation of that falsehood.)

So, propositional omniscience should at least be:

  1. x is omniscient iff x occurrently knows every truth for sure and has no degree of belief in any falsehood.

And, of course, propositional omniscience is unlikely to be all of omniscience.

1 comment:

Michael Gonzalez said...

This teases out some interesting concepts about knowledge. I think your distinction between knowing and knowing concurrently may need some clarification, since, even if I can't always recall everything I know right away, I don't cease to know them. If "memory" means "knowledge retained", then omniscience includes having a perfect memory. Whether there also needs to be perfect (immediate) recollection... I guess one could insist on that for omniscience.

Certainty seems to be an entirely different matter. Isn't "credence level" about beliefs? How does one measure the credence level of "being aware that proposition X is true"?