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18904
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'Predicable' terms come in charged pairs, with one the negation of the other [Sommers, by Engelbretsen]
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Full Idea:
Sommers took the 'predicable' terms of any language to come in logically charged pairs. Examples might be red/nonred, massive/massless, tied/untied, in the house/not in the house. The idea that terms can be negated was essential for such pairing.
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From:
report of Fred Sommers (Intellectual Autobiography [2005]) by George Engelbretsen - Trees, Terms and Truth 2
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A reaction:
If, as Rumfitt says, we learn affirmation and negation as a single linguistic operation, this would fit well with it, though Rumfitt doubtless (as a fan of classical logic) prefers to negation sentences.
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18895
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Logic which maps ordinary reasoning must be transparent, and free of variables [Sommers]
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Full Idea:
What would a 'laws of thought' logic that cast light on natural language deductive thinking be like? Such a logic must be variable-free, conforming to normal syntax, and its modes of reasoning must be transparent, to make them virtually instantaneous.
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From:
Fred Sommers (Intellectual Autobiography [2005], 'How We')
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A reaction:
This is the main motivation for Fred Sommers's creation of modern term logic. Even if you are up to your neck in modern symbolic logic (which I'm not), you have to find this idea appealing. You can't leave it to the psychologists.
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9390
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Logic guides thinking, but it isn't a substitute for it [Rumfitt]
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Full Idea:
Logic is part of a normative theory of thinking, not a substitute for thinking.
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From:
Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.13)
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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.
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18893
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Translating into quantificational idiom offers no clues as to how ordinary thinkers reason [Sommers]
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Full Idea:
Modern predicate logic's methods of justification, which involve translation into an artificial quantificational idiom, offer no clues to how the average person, knowing no logic and adhering to the vernacular, is so logically adept.
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From:
Fred Sommers (Intellectual Autobiography [2005], Intro)
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A reaction:
Of course, people are very logically adept when the argument is simple (because, I guess, they can test it against the world), but not at all good when the reasoning becomes more complex. We do, though, reason in ordinary natural language.
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18903
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Sommers promotes the old idea that negation basically refers to terms [Sommers, by Engelbretsen]
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Full Idea:
If there is one idea that is the keystone of the edifice that constitutes Sommers's united philosophy it is that terms are the linguistic entities subject to negation in the most basic sense. It is a very old idea, tending to be rejected in modern times.
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From:
report of Fred Sommers (Intellectual Autobiography [2005]) by George Engelbretsen - Trees, Terms and Truth 2
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A reaction:
Negation in modern logic is an operator applied to sentences, typically writing '¬Fa', which denies that F is predicated of a, with Fa being an atomic sentence. Do we say 'not(Stan is happy)', or 'not-Stan is happy', or 'Stan is not-happy'? Third one?
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18894
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Predicates form a hierarchy, from the most general, down to names at the bottom [Sommers]
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Full Idea:
We organise our concepts of predicability on a hierarchical tree. At the top are terms like 'interesting', 'exists', 'talked about', which are predicable of anything. At the bottom are names, and in between are predicables of some things and not others.
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From:
Fred Sommers (Intellectual Autobiography [2005], 'Category')
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A reaction:
The heirarchy seem be arranged simply by the scope of the predicate. 'Tallest' is predicable of anything in principle, but only of a few things in practice. Is 'John Doe' a name? What is 'cosmic' predicable of? Challenging!
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9389
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Vague membership of sets is possible if the set is defined by its concept, not its members [Rumfitt]
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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.
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From:
Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.5)
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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.
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2537
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Types are properties, and tokens are events. Are they split between mental and physical, or not? [Sturgeon]
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Full Idea:
The question is whether mental and physical types (which are properties) are distinct, and whether mental and physical tokens (which are events) are distinct.
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From:
Scott Sturgeon (Matters of Mind [2000], Intro)
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A reaction:
Helpful. While the first one gives us the rather dodgy notion of 'property dualism', the second one seems to imply Cartesian dualism, if the events really are distinct. It seems to me that thought is an aspect of brain events, not a distinct event.
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2535
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The main argument for physicalism is its simple account of causation [Sturgeon]
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Full Idea:
The dominant empirical argument for physicalism is the Overdetermination Argument: physics is closed and complete, mind is causally efficacious, the world isn't choc-full of overdetermination, so the mind is physical as well.
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From:
Scott Sturgeon (Matters of Mind [2000], Intro)
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A reaction:
I find this argument utterly convincing. The idea that there is only one thing which is outside the interconnected causal nexus which seems to constitute the rest of reality, and that is a piece of meat inside our heads, strikes me as totally ridiculous.
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