8945
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Fuzzy logic has many truth values, ranging in fractions from 0 to 1 [Fisher]
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Full Idea:
In fuzzy logic objects have properties to a greater or lesser degree, and truth values are given as fractions or decimals, ranging from 0 to 1. Not-p is defined as 1-p, and other formula are defined in terms of maxima and minima for sets.
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From:
Jennifer Fisher (On the Philosophy of Logic [2008], 07.II)
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A reaction:
The question seems to be whether this is actually logic, or a recasting of probability theory. Susan Haack attacks it. If logic is the study of how truth is preserved as we move between propositions, then 0 and 1 need a special status.
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8951
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Classical logic is: excluded middle, non-contradiction, contradictions imply all, disjunctive syllogism [Fisher]
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Full Idea:
For simplicity, we can say that 'classical logic' amounts to the truth of four sentences: 1) either p or not-p; 2) it is not the case that both p and not-p; 3) from p and not-p, infer q; 4) from p or q and not-p, infer q.
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From:
Jennifer Fisher (On the Philosophy of Logic [2008], 12.I)
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A reaction:
[She says there are many ways of specifying classical logic] Intuition suggests that 2 and 4 are rather hard to dispute, while 1 is ignoring some grey areas, and 3 is totally ridiculous. There is, of course, plenty of support for 3!
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8950
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Logic formalizes how we should reason, but it shouldn't determine whether we are realists [Fisher]
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Full Idea:
Even if one is inclined to be a realist about everything, it is hard to see why our logic should be the determiner. Logic is supposed to formalize how we ought to reason, but whether or not we should be realists is a matter of philosophy, not logic.
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From:
Jennifer Fisher (On the Philosophy of Logic [2008], 09.I)
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A reaction:
Nice to hear a logician saying this. I do not see why talk in terms of an object is a commitment to its existence. We can discuss the philosopher's stone, or Arthur's sword, or the Loch Ness monster, or gravitinos, with degrees of commitment.
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8944
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Vagueness can involve components (like baldness), or not (like boredom) [Fisher]
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Full Idea:
Vague terms come in at least two different kinds: those whose constituent parts come in discrete packets (bald, rich, red) and those that don't (beauty, boredom, niceness).
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From:
Jennifer Fisher (On the Philosophy of Logic [2008], 07.II)
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A reaction:
The first group seem to be features of the external world, and the second all occur in the mind. Baldness may be vague, but presumably hairs are (on the whole) not. Nature doesn't care whether someone is actually 'bald' or not.
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12298
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Genuine motion, rather than variation of position, requires the 'entire presence' of the object [Fine,K]
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Full Idea:
In order to have genuine motion, rather than mere variation in position, it is necessary that the object should be 'entirely present' at each moment of the change. Thus without entire presence, or existence, genuine motion will not be possible.
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From:
Kit Fine (In Defence of Three-Dimensionalism [2006], p.6)
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A reaction:
See Idea 4786 for a rival view of motion. Of course, who says we have to have Kit Fine's 'genuine' motion, if some sort of ersatz motion still gets you to work in the morning?
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12296
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4-D says things are stretched in space and in time, and not entire at a time or at a location [Fine,K]
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Full Idea:
Four-dimensionalists have thought that a material thing is as equally 'stretched out' in time as it is in space, and that there is no special way in which it is entirely present at a moment rather than at a position.
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From:
Kit Fine (In Defence of Three-Dimensionalism [2006], p.1)
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A reaction:
Compare his definition of 3-D in Idea 12295. The 4-D is contrary to our normal way of thinking. Since I don't think the future exists, I presume that if I am a 4-D object then I have to say that I don't yet exist, and I disapprove of such talk.
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18882
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You can ask when the wedding was, but not (usually) when the bride was [Fine,K, by Simons]
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Full Idea:
Fine says it is acceptable to ask when a wedding was and where it was, and it is acceptable to ask or state where the bride was (at a certain time), but not when she was.
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From:
report of Kit Fine (In Defence of Three-Dimensionalism [2006], p.18) by Peter Simons - Modes of Extension: comment on Fine p.18
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A reaction:
This is aimed at three-dimensionalists who seem to think that a bride is a prolonged event, just as a wedding is. Fine is, interestingly, invoking ordinary language. When did the wedding start and end? When was the bride's birth and death?
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12297
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Three-dimensionalist can accept temporal parts, as things enduring only for an instant [Fine,K]
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Full Idea:
Even if one is a three-dimensionalist, one might affirm the existence of temporal parts, on the grounds that everything merely endures for an instant.
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From:
Kit Fine (In Defence of Three-Dimensionalism [2006], p.2)
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A reaction:
This seems an important point, as belief in temporal parts is normally equated with four-dimensionalism (see Idea 12296). The idea is that a thing might be 'entirely present' at each instant, only to be replaced by a simulacrum.
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