Omniscience: unlimited knowledge. Not to be confounded with ►infallibility, although it is usually construed as including the latter.
In theology, omniscience is the possession by a
►divine being of complete knowledge of all states of the world -- including the thoughts of human beings -- be they past, present, or future.
God is said to exercise His ►omnipotence on the basis of this divine kind of knowledge.
The Omniscient Quiz Master
This situation leads to a dilemma in the following sense: Either it is possible for you to falsify the quiz master's prediction by making the opposite choice from the one he anticipated, or it is not. If it is possible, then the quiz master lacks complete knowledge of your character and so is not omniscient after all. If it is not, the question is why not; what accounts for the infallibility of the quiz master's predictions? Only two answers seem to be available. The first is that when you make your choice, you retroactively cause the quiz master to make the prediction he makes -- to make the prediction he made. While the notion of backward causation is not entirely without defenders, it is fairly uncontroversial to rule it out as absurd and thus to reject this answer. That leaves us with the second answer, which is that the quiz master's prediction is based on awareness of circumstances present at the time of the prediction that render your eventually choosing as he now predicts inevitable. Your choosing as you do would have to be predetermined. Thus, the idea of omniscience implies a completely predetermined world (►Laplace's demon) and thereby rules out choices, including choices between good and evil, that are not determined by prior circumstances. Although this has long been a subject of considerable controversy, many take this to be equivalent to denying free choice or freedom of will (the controversy being over whether freedom is compatible with being causally determined). This is why some theologians do not include knowledge of the future in God's omniscience in the first place. According to this weaker definition of omniscience, even a god who knew every fact about the past and present may be taken by surprise by human decisions that he had not predicted.
This is not the only problem with omniscience, however. Even the present can be known to an omniscient being only to a limited extent, as Gödel and Turing proved in 1930 and 1936, respectively. Even if God tried really hard, he would not be able to decide the truth or falsity of the ►continuum hypothesis. And if you present to God a computer program, He will often not be able to tell whether it contains a ►bug.
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