Tuesday, July 2, 2013

Guises and omniscience

Guise theorists think that "London is beautiful" and "Londres est belle" express the same proposition, but under two different guises. That's what makes it possible for Pierre to affirm the first statement (he does so under the "London" guise) while denying the other (under the "Londres" guise), without being irrational, if he doesn't know that London is Londres.

A standard definition of omniscience is:

  1. An omniscient being is one that knows every truth and believes only truths.
But given guise theory, this is insufficient. We have two natural ways to extend (1):
  1. An omniscient being is one that knows all truths under all their guises and believes only truths.
  2. An omniscient being is one that knows every truth under some guise or other and believes only truths.
Now, (3) seems insufficient for characterizing omniscience given guise theory. Suppose Pierre thinks that London is beautiful, but suspends judgment over whether Londres est belle. Surely his ignorance of whether Londres est belle suffices to render Pierre non-omniscient, even though he does believe the relevant proposition under some guise.

If we take (2), however, then we get an interesting result: If there is an omniscient being, there are no creaturely essentially private guises. An essentially private guise would be one that only one individual can believe something under. A creaturely one would be one where that individual is a creature. For if there were any creaturely essentially private guises, there would surely be some truths under them, and so by (2) God would know these truths under these guises, contrary to the privacy of the guises.

The most plausible kind of private guise would be "I". One might think that if I believe that I now typing, while you can believe the same proposition that I believe, you cannot believe it under the same guise. To believe it under the guise corresponding to "He is now typing" or "Alex is now typing" is to believe it under a different guise. Otherwise guise theory can't solve the Pierre problem. For it is possible for me to believe that I am now typing without believing "He (Alex) is now typing" or "Alex is now typing". If (2) is true and there is an omniscient being, then "I" is not an essentially private guise. That is surprising.

Moreover, one might think that there are guises which are essentially tied to certain experiences. Suppose I am suffering an odd pain. I believe the necessary truth "This is a pain" where the "This" refers to the pain under a guise whose grasp by me depends on my actually having or remembering a pain like that. If a being exists that is essentially omniscient, doesn't necessarily suffer and essentially lacks false memories, then such a being would have to be able to grasp "This is a pain" propositions under such pain-guises without either having the pains or remembering them.

So adopting (2) leads to surprising consequences for guise theory. Given the plausibility of the possibility of an omniscient being, this is a problem for guise theory.

Is there an alternative to (2) and (3)? Maybe one could say that an omniscient being knows truths under some divine guises which are richer than the guises under which we know things. Thus, perhaps God doesn't know that I am typing and that this is a pain under the guise under which I know it, but he knows them under a richer guise. The challenge here would be to try to work out what the greater richness of guise could be, without it being some kind of inclusion of the more private-seeming guises.

Of course, one could adopt (2) and simply accept the surprising consequences. Surprising consequences may be some evidence against a theory, but they can be far from refuting it.

Nor will abandoning guise theory get out of these problems. Guises were introduced to solve certain problems, like how it is possible to rationally believe "I am now typing" without believing "Alex is now typing" (say, I've forgotten my name). These problems still need a solution. A Fregean solution will say that all these sentences express different propositions. Fine. But the intuitions that supported privacy of some guises will now support the privacy of the corresponding propositions.

So, the existence of an omniscient being shows that some things that seemed to be private aren't.


William said...

Perhaps relativity and the frame of reference of "I" applies here. "I" may believe that I am traveling at a certain velocity, and another person may correctly believe that I have a different velocity, from their point of view.

The super-guise would be knowing their different frames of reference without being bound to any one frame.

God may know all of these guises, yet he does not need to believe that he has all these different velocities, himself, does he?

Then, knowing "I" am typing is one of many frames of reference that God knows but is not restricted by.

Daniel-OmniLingua said...

Omniscience is defined, to begin with, the so knowing of all basic, or irreducible (non-contingent), truths as to be equivalent to those truths. The key here is that omniscience is not 'knowledge writ generic' but 'knowledge writ Ground of all other being'. This constitutes the singular epistemologically most privileged position.

Beyond this, omniscience also includes *effectively* sufficient knowledge of all basic contingent truths, in which 'effective' is here defined as sufficiently serving some end. This is the other side of the coin of having created something.

Beyond these two sides of the coin may be thought the 'physics of the toss' (note that the second side, above, implies effective omniscience regarding this tossing).

Dagmara Lizlovs said...

"London is beautiful". That has not been my experience of London. Crowded with wall to wall traffic. As bad as New York City. I found the air in the Underground a bit heavy to breath.

"Alex is now typing" (say, I've forgotten my name). - You're too young to be having those problems.