Online research in philosophy

In Atheism: A Philosophical Justification, Michael Martin argues that to posit a God that is both omnipotent and omniscient is philosophically incoherent. I challenge this argument by proposing that a God who is necessarily omniscient is more powerful than a God who is contingently omniscient. I then argue that being omnipotent entails being omniscient by showing that for an all-powerful being to be all-powerful in any meaningful way, it must possess complete knowledge about all states of affairs and thus must be understood to be omniscient.

Donald Davidson has argued that 'most of our beliefs must be true' and that global scepticism is therefore false. Davidson's arguments to this conclusion often seem to depend on externalist considerations. Davidson's position has been criticised, however, on the grounds that he does not defeat the sceptic, but rather already assumes the falsity of scepticism through his appeal to externalism. Indeed, it has been claimed that far from defeating the sceptic Davidson introduces an even more extreme version of scepticism according to which we cannot even know the contents of our own minds. This paper argues that these criticisms are mistaken and that Davidson does indeed have grounds to argue that scepticism is false. The externalism that figures in Davidson's antisceptical arguments is shown to be merely an element in Davidson's overall holism according to which the very possibility of having beliefs that could be true or false depends on most of those beliefs being true and their contents known.

I’m going to argue that omniscience is impossible and therefore that there is no God. The argument turns on the notion of grounding. After illustrating and clarifying that notion, I’ll start the argument in earnest. The first step will be to lay out five claims, one of which is the claim that there is an omniscient being, and the other four of which are claims about grounding. I’ll prove that these five claims are jointly inconsistent. Then I’ll argue for the truth of each of them except the claim that there is an omniscient being. From these arguments it follows that there are no omniscient beings and thus that there is no God.

The concepts of omniscience and omnipotence are defined in 2 ? 2 ordinal games, and implications for the optimal play of these games, when one player is omniscient or omnipotent and the other player is aware of his omniscience or omnipotence, are derived. Intuitively, omniscience allows a player to predict the strategy choice of an opponent in advance of play, and omnipotence allows a player, after initial strategy choices are made, to continue to move after the other player is forced to stop. Omniscience and its awareness by an opponent may hurt both players, but this problem can always be rectified if the other player is omniscient. This pathology can also be rectified if at least one of the two players is omnipotent, which can override the effects of omniscience. In some games, one player's omnipotence ? versus the other's ? helps him, whereas in other games the outcome induced does not depend on which player is omnipotent. Deducing whether a player is superior (omniscient or omnipotent) from the nature of his game playing alone raises several problems, however, suggesting the difficulty of devising tests for detecting superior ability in games.

I once came across a Mark Twain story in which a character said something to the effect that the one thing God didn’t know was that he was not all-knowing. As an argument against omniscience, Twain’s one-liner doesn’t amount to much. Thinking about it, however, led to the kind of puzzles I explore here. Some puzzles about omniscience are connected to other issues, such as whether all claims about the future presently have truth-values. Those in turn are connected to deep issues in the metaphysics of time. (Is the future real, and, if so, in what sense?) Others are connected to questions about knowledge by acquaintance1—such as whether God must, in order to be omniscient, know what it is like, say, to be guilty or to have a limited perspective, and whether God can know such things without actually being guilty or having a limited perspective.

My concern is with a different kind of puzzle, having to do with propositional knowledge, knowledge of facts that can be represented by that-clauses in sentences such as ‘John knows that the world is round.’ I shall focus upon questions about a supposedly omniscient being who propositionally knows the truth about all current states of affairs. I shall argue that there is no such being.

The publication of Davidson 2001, anthologizing articles from the 1980s and 1990s, encourages reconsidering arguments contained in them. One such argument is Davidson’s omniscient-interpreter argument (‘OIA’) in Davidson 1983. The OIA allegedly establishes that it is necessary that most beliefs are true. Thus the omniscient interpreter, revived in 2001 and now 20 years old, was born to answer the skeptic. In Part I of this paper, I consider charges that the OIA establishes only that it is possible that most beliefs are true; if correct, then it is also possibly the case that most beliefs are false—the skeptic’s very position. Next, I consider two responses on Davidson’s behalf, showing that each fails. In Part II, I show that the OIA establishes neither that it is necessarily merely possibly but actually the case that most beliefs are true. I then conclude that this is enough to answer the skeptic.

l examine the “omniscient interpreter” (OI) argument against scepticism that Donald Davidson published in 1977 only to retract it twenty-two years later. I argue that the argument’s persuasiveness has been underestimated. I defend it against the charges that Davidson assumes the actual existence of an OI and that Davidson’s other philosophical commitments are incompatible with the very conceivability of an OI. The argument’s surface implausibility derivesfrom Davidson’s suggestion that an OI would attribute beliefs using the same methods as afallible human interpreter. But this problem can be remedied via the adoption of an ambiguity theory of belief.J’examine l’argument de “l’interprète omniscient” (IO) contre les objections sceptiques formulées par Donald Davidson en 1977, qu’il a rétractées vingt-deux ans plus tard. Je soutiens que la force de cet argument a été sous-estimée. Je m’inscris en faux contre les critiques voulant que Davidson ait supposé l’existence effective de l’IO, et que les autres croyances philosophiques de Davidson soientincompatibles avec la possibilité de concevoir l’idée d’un IO. Si l’argument semble peu plausible à prime abord, c’est que Davidson a suggéré qu’un IO attribuait les croyances en utilisant les mêmes méthodes qu’un interprète humain faillible. On peut remédier à ce problème en adoptant une théorie de l’ambiguïté des croyances.