|
13342
|
Carnap defined consequence by contradiction, but this is unintuitive and changes with substitution [Tarski on Carnap]
|
|
Full Idea:
Carnap proposed to define consequence as 'sentence X follows from the sentences K iff the sentences K and the negation of X are contradictory', but 1) this is intuitively impossible, and 2) consequence would be changed by substituting objects.
|
|
From:
comment on Rudolph Carnap (The Logical Syntax of Language [1934], p.88-) by Alfred Tarski - The Concept of Logical Consequence p.414
|
|
A reaction:
This seems to be the first step in the ongoing explicit discussion of the nature of logical consequence, which is now seen by many as the central concept of logic. Tarski brings his new tool of 'satisfaction' to bear.
|
|
13251
|
Each person is free to build their own logic, just by specifying a syntax [Carnap]
|
|
Full Idea:
In logic, there are no morals. Everyone is at liberty to build his own logic, i.e. his own form of language. All that is required is that he must state his methods clearly, and give syntactical rules instead of philosophical arguments.
|
|
From:
Rudolph Carnap (The Logical Syntax of Language [1934], §17), quoted by JC Beall / G Restall - Logical Pluralism 7.3
|
|
A reaction:
This is understandable, but strikes me as close to daft relativism. If I specify a silly logic, I presume its silliness will be obvious. By what criteria? I say the world dictates the true logic, but this is a minority view.
|
|
12897
|
To say S knows P, but cannot eliminate not-P, sounds like a contradiction [Lewis]
|
|
Full Idea:
If you claim that S knows that P, and yet grant that S cannot eliminate a certain possibility of not-P, it certainly seems as if you have granted that S does not after all know that P. To speak of fallible knowledge just sounds contradictory.
|
|
From:
David Lewis (Elusive Knowledge [1996], p.419)
|
|
A reaction:
Starting from this point, fallibilism seems to be a rather bold move. The only sensible response seems to be to relax the requirement that not-P must be eliminable. Best: in one epistemic context P, in another not-P.
|
|
19562
|
We have knowledge if alternatives are eliminated, but appropriate alternatives depend on context [Lewis, by Cohen,S]
|
|
Full Idea:
S knows P if S's evidence eliminates every alternative. But the nature of the alternatives depends on context. So for Lewis, the context sensitivity of 'knows' is a function of contextual restrictions ln the domain of quantification.
|
|
From:
report of David Lewis (Elusive Knowledge [1996]) by Stewart Cohen - Contextualism Defended (and reply) 1
|
|
A reaction:
A typical modern attempt to 'regiment' a loose term like 'context'. That said, I like the idea. I'm struck by how the domain varies during a conversation (as in 'what we are talking about'). Domains standardly contain 'objects', though.
|
|
7903
|
The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna]
|
|
Full Idea:
The six perfections are of giving, morality, patience, vigour, meditation, and wisdom.
|
|
From:
Nagarjuna (Mahaprajnaparamitashastra [c.120], 88)
|
|
A reaction:
What is 'morality', if giving is not part of it? I like patience and vigour being two of the virtues, which immediately implies an Aristotelian mean (which is always what is 'appropriate').
|