18 ideas
| 15163 | The interest of quantified modal logic is its metaphysical necessity and essentialism [Soames] |
| Full Idea: The chief philosophical interest in quantified modal logic lies with metaphysical necessity, essentialism, and the nontrivial modal de re. | |
| From: Scott Soames (Philosophy of Language [2010], 3.1) |
| 17610 | The Axiom of Choice paradoxically allows decomposing a sphere into two identical spheres [Maddy] |
| Full Idea: One feature of the Axiom of Choice that troubled many mathematicians was the so-called Banach-Tarski paradox: using the Axiom, a sphere can be decomposed into finitely many parts and those parts reassembled into two spheres the same size as the original. | |
| From: Penelope Maddy (Defending the Axioms [2011], 1.3) | |
| A reaction: (The key is that the parts are non-measurable). To an outsider it is puzzling that the Axiom has been universally accepted, even though it produces such a result. Someone can explain that, I'm sure. |
| 17620 | Critics of if-thenism say that not all starting points, even consistent ones, are worth studying [Maddy] |
| Full Idea: If-thenism denies that mathematics is in the business of discovering truths about abstracta. ...[their opponents] obviously don't regard any starting point, even a consistent one, as equally worthy of investigation. | |
| From: Penelope Maddy (Defending the Axioms [2011], 3.3) | |
| A reaction: I have some sympathy with if-thenism, in that you can obviously study the implications of any 'if' you like, but deep down I agree with the critics. |
| 15158 | Indefinite descriptions are quantificational in subject position, but not in predicate position [Soames] |
| Full Idea: The indefinite description in 'A man will meet you' is naturally treated as quantificational, but an occurrence in predicative position, in 'Jones is not a philosopher', doesn't have a natural quantificational counterpart. | |
| From: Scott Soames (Philosophy of Language [2010], 1.23) |
| 15157 | Recognising the definite description 'the man' as a quantifier phrase, not a singular term, is a real insight [Soames] |
| Full Idea: Recognising the definite description 'the man' as a quantifier phrase, rather than a singular term, is a real insight. | |
| From: Scott Soames (Philosophy of Language [2010], 1.22) | |
| A reaction: 'Would the man who threw the stone come forward' seems like a different usage from 'would the man in the black hat come forward'. |
| 15156 | The universal and existential quantifiers were chosen to suit mathematics [Soames] |
| Full Idea: Since Frege and Russell were mainly interested in formalizing mathematics, the only quantifiers they needed were the universal and existential one. | |
| From: Scott Soames (Philosophy of Language [2010], 1.22) |
| 17605 | Hilbert's geometry and Dedekind's real numbers were role models for axiomatization [Maddy] |
| Full Idea: At the end of the nineteenth century there was a renewed emphasis on rigor, the central tool of which was axiomatization, along the lines of Hilbert's axioms for geometry and Dedekind's axioms for real numbers. | |
| From: Penelope Maddy (Defending the Axioms [2011], 1.3) |
| 17625 | If two mathematical themes coincide, that suggest a single deep truth [Maddy] |
| Full Idea: The fact that two apparently fruitful mathematical themes turn out to coincide makes it all the more likely that they're tracking a genuine strain of mathematical depth. | |
| From: Penelope Maddy (Defending the Axioms [2011], 5.3ii) |
| 17615 | Every infinite set of reals is either countable or of the same size as the full set of reals [Maddy] |
| Full Idea: One form of the Continuum Hypothesis is the claim that every infinite set of reals is either countable or of the same size as the full set of reals. | |
| From: Penelope Maddy (Defending the Axioms [2011], 2.4 n40) |
| 17618 | Set-theory tracks the contours of mathematical depth and fruitfulness [Maddy] |
| Full Idea: Our set-theoretic methods track the underlying contours of mathematical depth. ...What sets are, most fundamentally, is markers for these contours ...they are maximally effective trackers of certain trains of mathematical fruitfulness. | |
| From: Penelope Maddy (Defending the Axioms [2011], 3.4) | |
| A reaction: This seems to make it more like a map of mathematics than the actual essence of mathematics. |
| 17614 | The connection of arithmetic to perception has been idealised away in modern infinitary mathematics [Maddy] |
| Full Idea: Ordinary perceptual cognition is most likely involved in our grasp of elementary arithmetic, but ...this connection to the physical world has long since been idealized away in the infinitary structures of contemporary pure mathematics. | |
| From: Penelope Maddy (Defending the Axioms [2011], 2.3) | |
| A reaction: Despite this, Maddy's quest is for a 'naturalistic' account of mathematics. She ends up defending 'objectivity' (and invoking Tyler Burge), rather than even modest realism. You can't 'idealise away' the counting of objects. I blame Cantor. |
| 8978 | Events are made of other things, and are not fundamental to ontology [Bennett] |
| Full Idea: Events are not basic items in the universe; they should not be included in any fundamental ontology...all the truths about them are entailed by and explained and made true by truths that do not involve the event concept. | |
| From: Jonathan Bennett (Events and Their Names [1988], p.12), quoted by Peter Simons - Events 3.1 | |
| A reaction: Given the variable time spans of events, their ability to coincide, their ability to contain no motion, their blatantly conventional component, and their recalcitrance to individuation, I say Bennett is right. |
| 15162 | We understand metaphysical necessity intuitively, from ordinary life [Soames] |
| Full Idea: Our understanding of metaphysical necessity is intuitive - drawn from our ordinary thought and talk. | |
| From: Scott Soames (Philosophy of Language [2010], 3.1) | |
| A reaction: This, of course, is a good reason for analytic philosophers to dislike metaphysical necessity. |
| 15161 | There are more metaphysically than logically necessary truths [Soames] |
| Full Idea: The set of metaphysically necessary truths is larger than the set of logically necessary truths. | |
| From: Scott Soames (Philosophy of Language [2010], 3.1) | |
| A reaction: Likewise, the set of logically possible truths is much larger than the set of metaphysically possible truths. If a truth is logically necessary, it will clearly be metaphysically necessary. Er, unless it is necessitated by daft logic... |
| 15152 | To study meaning, study truth conditions, on the basis of syntax, and representation by the parts [Soames] |
| Full Idea: The systematic study of meaning requires a framework for specifying the truth conditions of sentences on the basis of their syntactic structure, and the representational contents of their parts. | |
| From: Scott Soames (Philosophy of Language [2010], Intro) | |
| A reaction: Soames presents this as common sense, on the first page of his book, and it is hard to disagree. Representation will shade off into studying the workings of the mind. Fodor seems a good person to start with. |
| 15153 | Tarski's account of truth-conditions is too weak to determine meanings [Soames] |
| Full Idea: The truth conditions provided by Tarski's theories (based on references of subsentential constituents) are too weak to determine meanings, because they lacked context-sensitivity and various forms of intensionality. | |
| From: Scott Soames (Philosophy of Language [2010], Intro) | |
| A reaction: Interesting. This suggests that stronger modern axiomatic theories of truth might give a sufficient basis for a truth conditions theory of meaning. Soames says possible worlds semantics was an attempt to improve things. |
| 15154 | We should use cognitive states to explain representational propositions, not vice versa [Soames] |
| Full Idea: Instead of explaining the representationality of sentences and cognitive states in terms of propositions, we must explain the representationality of propositions in terms of the representationality of the relevant cognitive states. | |
| From: Scott Soames (Philosophy of Language [2010], Intro) | |
| A reaction: Music to my ears. I am bewildered by this Russellian notion of a 'proposition' as some abstract entity floating around in the world waiting to be expressed. The vaguer word 'facts' (and false facts?) will cover that. It's Frege's fault. |
| 10364 | Facts are about the world, not in it, so they can't cause anything [Bennett] |
| Full Idea: Facts are not the sort of item that can cause anything. A fact is a true proposition (they say); it is not something in the world but is rather something about the world. | |
| From: Jonathan Bennett (Events and Their Names [1988], p.22), quoted by Jonathan Schaffer - The Metaphysics of Causation 1.1 | |
| A reaction: Compare 10361. Good argument, but maybe 'fact' is ambiguous. See Idea 10365. Events are said to be more concrete, and so can do the job, but their individuation also seems to depend on a description (as Davidson has pointed out). |