18909
|
Aristotelian sentences are made up by one of four 'formative' connectors [Aristotle, by Engelbretsen]
|
|
Full Idea:
For Aristotle there are four formatives for sentences: 'belongs to some', 'belongs to every', 'belongs to no', and 'does not belong to every'. These are 'copulae'. Aristotle would have written 'wise belongs to some man'.
|
|
From:
report of Aristotle (Prior Analytics [c.328 BCE]) by George Engelbretsen - Trees, Terms and Truth 3
|
|
A reaction:
A rather set-theoretic reading. This invites a Quinean scepticism about whether wisdom is some entity which can 'belong' to a person. It makes trope theory sound attractive, offering a unique wisdom that is integrated into that particular person.
|
8080
|
Aristotelian identified 256 possible syllogisms, saying that 19 are valid [Aristotle, by Devlin]
|
|
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.
|
|
From:
report of Aristotle (Prior Analytics [c.328 BCE]) by Keith Devlin - Goodbye Descartes Ch.2
|
|
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.
|
13912
|
Aristotle replaced Plato's noun-verb form with unions of pairs of terms by one of four 'copulae' [Aristotle, by Engelbretsen/Sayward]
|
|
Full Idea:
Aristotle replaced the Platonic noun-verb account of logical syntax with a 'copular' account. A sentence is a pair of terms bound together logically (not necessarily grammatically) by one of four 'logical copulae' (every, none, some, not some).
|
|
From:
report of Aristotle (Prior Analytics [c.328 BCE]) by Engelbretsen,G/Sayward,C - Philosophical Logic: Intro to Advanced Topics 8
|
|
A reaction:
So the four copulas are are-all, are-never, are-sometimes, and are-sometime-not. Consider 'men' and 'mortal'. Alternatively, Idea 18909.
|
9403
|
There are three different deductions for actual terms, necessary terms and possible terms [Aristotle]
|
|
Full Idea:
Since to belong, to belong of necessity, and to be possible to belong are different, ..there will be different deductions for each; one deduction will be from necessary terms, one from terms which belong, and one from possible terms.
|
|
From:
Aristotle (Prior Analytics [c.328 BCE], 29b29-35)
|
|
A reaction:
Fitting and Mendelsohn cite this as the earliest thoughts on modal logic. but Kneale and Kneale say that Aristotle got into a muddle, and so was unable to create a workable system.
|
11148
|
Deduction is when we suppose one thing, and another necessarily follows [Aristotle]
|
|
Full Idea:
A deduction is a discourse in which, certain things having been supposed, something different from the things supposed results of necessity because these things are so.
|
|
From:
Aristotle (Prior Analytics [c.328 BCE], 24b18)
|
|
A reaction:
Notice that it is modal ('suppose', rather than 'know'), that necessity is involved, which is presumably metaphysical necessity, and that there are assumptions about what would be true, and not just what follows from what.
|
8079
|
Aristotelian logic has two quantifiers of the subject ('all' and 'some') [Aristotle, by Devlin]
|
|
Full Idea:
Aristotelian logic has two quantifiers of the subject ('all' and 'some'), and two ways to combine the subject with the predicate ('have', and 'have not'), giving four propositions: all-s-have-p, all-s-have-not-p, some-s-have-p, and some-s-have-not-p.
|
|
From:
report of Aristotle (Prior Analytics [c.328 BCE]) by Keith Devlin - Goodbye Descartes Ch.2
|
|
A reaction:
Frege seems to have switched from 'some' to 'at-least-one'. Since then other quantifiers have been proposed. See, for example, Ideas 7806 and 6068.
|
18911
|
Linguistic terms form a hierarchy, with higher terms predicable of increasing numbers of things [Aristotle, by Engelbretsen]
|
|
Full Idea:
According to Aristotle, the terms of a language form a finite hierarchy, where the higher terms are predicable of more things than are lower terms.
|
|
From:
report of Aristotle (Prior Analytics [c.328 BCE]) by George Engelbretsen - Trees, Terms and Truth 3
|
|
A reaction:
I would be a bit cautious about placing something precisely in a hierarchy according to how many things it can be predicated of. It is a start, though, in trying to give a decent account of generality, which is a major concept in philosophy.
|
7535
|
If all beliefs are propositional, then belief and judgement are the same thing [Monk]
|
|
Full Idea:
Whether the words 'belief' and 'judgement' mean the same thing is a moot point. Traditionally, a judgement is the assent of mind to a proposition. If one thinks that all beliefs are propositional, then beliefs and judgements are the same thing.
|
|
From:
Ray Monk (Bertrand Russell: Spirit of Solitude [1996], Ch.19 n6)
|
|
A reaction:
If I think I have put a bit too much toothpaste on my brush, that strikes me as a non-propositional judgement, even though it could be spelled out as a proposition. But it also strikes me as a belief.
|