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Single Idea 8080
[filed under theme 4. Formal Logic / A. Syllogistic Logic / 1. Aristotelian Logic
]
Full Idea
Aristotle identified four 'figures' of argument, based on combinations of Subject (S) and Predicate (P) and Middle term (M). The addition of 'all' and 'some', and 'has' and 'has not' got the property, resulted in 256 possible syllogisms, 19 of them valid.
Gist of Idea
Aristotelian identified 256 possible syllogisms, saying that 19 are valid
Source
report of Aristotle (Prior Analytics [c.328 BCE]) by Keith Devlin - Goodbye Descartes Ch.2
Book Ref
Devlin,Keith: 'Goodbye Descartes: the end of logic' [Wiley 1997], p.42
A Reaction
[Compressed version of Devlin] What Aristotle did was astonishing, and must be one of the key ideas of western civilization, even though a lot of his assumptions have been revised or rejected.
The
15 ideas
from 'Prior Analytics'
11060
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Aristotelian syllogisms are three-part, subject-predicate, existentially committed, with laws of thought
[Aristotle, by Hanna]
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13819
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Aristotle's said some Fs are G or some Fs are not G, forgetting that there might be no Fs
[Bostock on Aristotle]
|
22271
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Aristotle was the first to use schematic letters in logic
[Aristotle, by Potter]
|
18909
|
Aristotelian sentences are made up by one of four 'formative' connectors
[Aristotle, by Engelbretsen]
|
8080
|
Aristotelian identified 256 possible syllogisms, saying that 19 are valid
[Aristotle, by Devlin]
|
13912
|
Aristotle replaced Plato's noun-verb form with unions of pairs of terms by one of four 'copulae'
[Aristotle, by Engelbretsen/Sayward]
|
18896
|
Aristotle places terms at opposite ends, joined by a quantified copula
[Aristotle, by Sommers]
|
3300
|
Aristotle's logic is based on the subject/predicate distinction, which leads him to substances and properties
[Aristotle, by Benardete,JA]
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8079
|
Aristotelian logic has two quantifiers of the subject ('all' and 'some')
[Aristotle, by Devlin]
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18911
|
Linguistic terms form a hierarchy, with higher terms predicable of increasing numbers of things
[Aristotle, by Engelbretsen]
|
11149
|
Affirming/denying sentences are universal, particular, or indeterminate
[Aristotle]
|
11148
|
Deduction is when we suppose one thing, and another necessarily follows
[Aristotle]
|
9403
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There are three different deductions for actual terms, necessary terms and possible terms
[Aristotle]
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14641
|
A deduction is necessary if the major (but not the minor) premise is also necessary
[Aristotle]
|
8071
|
Aristotle listed nineteen valid syllogisms (though a few of them were wrong)
[Aristotle, by Devlin]
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