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wins', is true (always has been and ever will be) and the other is false (always has been and ever will be). Suppose 'A wins' is today true. Then whatever A does (or fails to do) today will make no difference; similarly, whatever B does (or fails to do) today will make no difference: the outcome is already settled. Or again, suppose 'A wins' is today false. Then no matter what A does today (or fails to do), it will make no difference; similarly, no matter what B does (or fails to do), it will make no difference: the outcome is already settled. Thus, if propositions bear their truth-values timelessly (or unchangingly and eternally), then planning, or as
Aristotle put it 'taking care', is illusory in its efficacy. The future will be what it will be, irrespective of our planning, intentions, etc.
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The conclusion is false, since, even though Mickey Mouse is over 35 years old, there is no logical necessity for him to be. Even though it is certainly true in this world, a possible world can exist in which Mickey Mouse is not yet 35 years old. If instead of adding a stipulation of necessity, the
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Two admirals, A and B, are preparing their navies for a sea battle tomorrow. The battle will be fought until one side is victorious. But the 'laws' of the excluded middle (no third truth-value) and of non-contradiction (not both truth-values), mandate that one of the propositions, 'A wins' and 'B
77:. A statement is considered necessarily true if and only if it is impossible for the statement to be untrue and that there is no situation that would cause the statement to be false. Some philosophers further argue that a necessarily true statement must be true in all
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gave the following example of how the modal fallacy can lead one to conclude that the future is already set, regardless of one's decisions; this is based on the "sea battle" example used by
Aristotle to discuss the
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In modal logic, there is an important distinction between what is logically necessary to be true and what is true but not logically necessary to be so. One common form is replacing
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401:. It is true here that only one of the statements "A wins" or "B wins" must be true. In other words, only one of
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argument just concluded that Mickey Mouse is 35 or older, it would be valid.
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A common example in everyday life might be the following:
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548:{\displaystyle \lnot \diamond (A\land B)}
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324:The President is at least 35 years old.
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264:{\displaystyle p\rightarrow \Box q}
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763:"Foreknowledge and Free Will"
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741:"The Modal Fallacy"
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808:Informal fallacies
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770:. Retrieved
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793:Modal logic
212:Description
73:necessarily
68:modal logic
787:Categories
701:References
205:contingent
772:26 August
746:26 August
675:◻
652:◻
629:⋄
606:⋄
537:∧
528:⋄
525:¬
515:is true)
460:∨
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409:⋄
256:◻
253:→
227:→
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184:⋄
161:⋄
138:¬
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644:implies
475:(either
724:29 July
346:in his
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44:Discuss
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242:with
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748:2017
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75:true
58:The
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351::
299:p
279:q
259:q
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230:q
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190:P
164:P
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115:P
92:P
46:)
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