|
9390
|
Logic guides thinking, but it isn't a substitute for it [Rumfitt]
|
|
Full Idea:
Logic is part of a normative theory of thinking, not a substitute for thinking.
|
|
From:
Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.13)
|
|
A reaction:
There is some sort of logicians' dream, going back to Leibniz, of a reasoning engine, which accepts propositions and outputs inferences. I agree with this idea. People who excel at logic are often, it seems to me, modest at philosophy.
|
|
9389
|
Vague membership of sets is possible if the set is defined by its concept, not its members [Rumfitt]
|
|
Full Idea:
Vagueness in respect of membership is consistency with determinacy of the set's identity, so long as a set's identity is taken to consist, not in its having such-and-such members, but in its being the extension of a concept.
|
|
From:
Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.5)
|
|
A reaction:
I find this view of sets much more appealing than the one that identifies a set with its members. The empty set is less of a problem, as well as non-existents. Logicians prefer the extensional view because it is tidy.
|
|
16973
|
Explain logical necessity by logical consequence, or the other way around? [Correia]
|
|
Full Idea:
One view is that logical consequence is to be understood in terms of logical necessity (some proposition holds necessarily, if some group of other propositions holds). Alternatively, logical necessity is a logical consequence of the empty set.
|
|
From:
Fabrice Correia (On the Reduction of Necessity to Essence [2012], 3)
|
|
A reaction:
I think my Finean preference is for all necessities to have a 'necessitator', so logical necessity results from logic in some way, perhaps from logical consequence, or from the essences of the connectives and operators.
|