20 ideas
| 15375 | If terms change their designations in different states, they are functions from states to objects [Fitting] |
| Full Idea: The common feature of every designating term is that designation may change from state to state - thus it can be formalized by a function from states to objects. | |
| From: Melvin Fitting (Intensional Logic [2007], 3) | |
| A reaction: Specifying the objects sounds OK, but specifying states sounds rather tough. |
| 15376 | Intensional logic adds a second type of quantification, over intensional objects, or individual concepts [Fitting] |
| Full Idea: To first order modal logic (with quantification over objects) we can add a second kind of quantification, over intensions. An intensional object, or individual concept, will be modelled by a function from states to objects. | |
| From: Melvin Fitting (Intensional Logic [2007], 3.3) |
| 15378 | Awareness logic adds the restriction of an awareness function to epistemic logic [Fitting] |
| Full Idea: Awareness logic enriched Hintikka's epistemic models with an awareness function, mapping each state to the set of formulas we are aware of at that state. This reflects some bound on the resources we can bring to bear. | |
| From: Melvin Fitting (Intensional Logic [2007], 3.6.1) | |
| A reaction: [He cites Fagin and Halpern 1988 for this] |
| 15379 | Justication logics make explicit the reasons for mathematical truth in proofs [Fitting] |
| Full Idea: In justification logics, the logics of knowledge are extended by making reasons explicit. A logic of proof terms was created, with a semantics. In this, mathematical truths are known for explicit reasons, and these provide a measure of complexity. | |
| From: Melvin Fitting (Intensional Logic [2007], 3.6.1) |
| 11026 | Classical logic is deliberately extensional, in order to model mathematics [Fitting] |
| Full Idea: Mathematics is typically extensional throughout (we write 3+2=2+3 despite the two terms having different meanings). ..Classical first-order logic is extensional by design since it primarily evolved to model the reasoning of mathematics. | |
| From: Melvin Fitting (Intensional Logic [2007], §1) |
| 11028 | λ-abstraction disambiguates the scope of modal operators [Fitting] |
| Full Idea: λ-abstraction can be used to abstract and disambiguate a predicate. De re is [λx◊P(x)](f) - f has the possible-P property - and de dicto is ◊[λxP(x)](f) - possibly f has the P-property. Also applies to □. | |
| From: Melvin Fitting (Intensional Logic [2007], §3.3) | |
| A reaction: Compare the Barcan formula. Originated with Church in the 1930s, and Carnap 1947, but revived by Stalnaker and Thomason 1968. Because it refers to the predicate, it has a role in intensional versions of logic, especially modal logic. |
| 21642 | If quantification is all substitutional, there is no ontology [Quine] |
| Full Idea: Ontology is meaningless for a theory whose only quantification is substitutionally construed. | |
| From: Willard Quine (Ontological Relativity [1968], p.64), quoted by Thomas Hofweber - Ontology and the Ambitions of Metaphysics 03.5.1 n18 | |
| A reaction: Hofweber views it as none the worse for that, since clearly lots of quantification has no ontological commitment at all. But he says it is rightly called 'a nominalists attempt at a free lunch'. |
| 1633 | Absolute ontological questions are meaningless, because the answers are circular definitions [Quine] |
| Full Idea: What makes ontological questions meaningless when taken absolutely is not universality but circularity. A question of the form "What is an F?" can only be answered with "An F is a G", which makes sense relative to the uncritical acceptance of G. | |
| From: Willard Quine (Ontological Relativity [1968], p.53) | |
| A reaction: This is too precise. No one takes such questions wholly as 'absolutes', but we don't accept G uncritically. We keep going, and the target is not a foundation, but coherence. |
| 18964 | Ontology is relative to both a background theory and a translation manual [Quine] |
| Full Idea: Ontology is doubly relative. Specifying the universe of a theory makes sense only relative to some background theory, and only relative to some choice of a manual of translation of one theory into another. | |
| From: Willard Quine (Ontological Relativity [1968], p.54) | |
| A reaction: People tend to forget about the double nature of Quine's notion of ontological commitment, and usually only talk about the commitment of the theory being employed. Why is the philosophical community not devoting itself to the study of tranlation manuals? |
| 18965 | We know what things are by distinguishing them, so identity is part of ontology [Quine] |
| Full Idea: We cannot know what something is without knowing how it is marked off from other things. Identity is thus of a piece with ontology. | |
| From: Willard Quine (Ontological Relativity [1968], p.55) | |
| A reaction: Actually it is failure of identity which seems to raise questions of individuation. If I say 'this apple is [pause] identical to this apple', I don't see how that helps me to individuate apples. |
| 15377 | Definite descriptions pick out different objects in different possible worlds [Fitting] |
| Full Idea: Definite descriptions pick out different objects in different possible worlds quite naturally. | |
| From: Melvin Fitting (Intensional Logic [2007], 3.4) | |
| A reaction: A definite description can pick out the same object in another possible world, or a very similar one, or an object which has almost nothing in common with the others. |
| 1634 | Two things are relative - the background theory, and translating the object theory into the background theory [Quine] |
| Full Idea: Relativity has two components: to the choice of a background theory, and to the choice of how to translate the object theory into the background theory. | |
| From: Willard Quine (Ontological Relativity [1968], p.67) |
| 5952 | Rather than being the whole soul, maybe I am its chief part? [Plutarch] |
| Full Idea: Is each of us not the soul, but the chief part of the soul, by which we think and reason and act, all the other parts of soul as well as of body being mere instruments of its power? | |
| From: Plutarch (74: Reply to Colotes [c.85], §1119) | |
| A reaction: Socrates is associated with the idea that I am my whole soul (Idea 1650). Plutarch represents an interesting development, which may lead both to the Christian 'soul' and to the Cartesian 'ego'. I think Plutarch is right, but what is the 'soul'? |
| 5951 | If atoms have no qualities, they cannot possibly produce a mind [Plutarch] |
| Full Idea: Perception, mind, intelligence and thought cannot so much as be conceived, even with the best will, as arising among void and atoms, things which taken separately have no quality. | |
| From: Plutarch (74: Reply to Colotes [c.85], §1112) | |
| A reaction: A nice articulation of the intuition of all anti-physicalists. Plutarch would have to rethink his position carefully if he learned of the sheer number of connections in the brain, and of the theory of natural selection. His challenge remains, though. |
| 8470 | Reference is inscrutable, because we cannot choose between theories of numbers [Quine, by Orenstein] |
| Full Idea: For Quine, we cannot sensibly ask which is the real number five, the Frege-Russell set or the Von Neumann one. There is no arithmetical or empirical way of deciding between the two. Reference is inscrutable. | |
| From: report of Willard Quine (Ontological Relativity [1968]) by Alex Orenstein - W.V. Quine Ch.3 | |
| A reaction: To generalise from a problem of reference in the highly abstract world of arithmetic, and say that all reference is inscrutable, strikes me as implausible. |
| 18963 | Indeterminacy translating 'rabbit' depends on translating individuation terms [Quine] |
| Full Idea: The indeterminacy between 'rabbit', 'rabbit stage' and the rest depended only on a correlative indeterminacy of translation of the English apparatus of individuation - pronouns, plurals, identity, numerals and so on. | |
| From: Willard Quine (Ontological Relativity [1968], p.35) | |
| A reaction: This spells out the problem a little better than in 'Word and Object'. I just don't believe these problems are intractable. Quine is like a child endlessly asking 'why?'. |
| 20796 | Action needs an affinity for a presentation, and an impulse toward the affinity [Plutarch] |
| Full Idea: The sceptics say there are three movements of the soul: presentation, impulse and assent. …And action requires two things: a presentation of something to which one has an affinity, and an impulse toward what is presented as an object of affinity. | |
| From: Plutarch (74: Reply to Colotes [c.85], 1122c) | |
| A reaction: Not much reasoning involved in this account, which the sceptics say is compatible with suspension of judgement. |
| 5948 | The good life involves social participation, loyalty, temperance and honesty [Plutarch] |
| Full Idea: To live the good life is to live a life of participation in society, of loyalty to friends, of temperance and honest dealing. | |
| From: Plutarch (74: Reply to Colotes [c.85], §1108) | |
| A reaction: 'Participation in society' is the interesting one. This might translate as 'doing your duty', or as 'leading a well-rounded life'. Solitude is wrong if you are indebted to others, and it is unhealthy if you are not. Is solitude really immoral, though? |
| 5950 | If only atoms exist, how do qualities arise when the atoms come together? [Plutarch] |
| Full Idea: If you accept atomism, you must show how bodies without quality have given rise to qualities of every kind by the mere fact of coming together. For example, how has the quality called 'hot' been imposed on the atoms? | |
| From: Plutarch (74: Reply to Colotes [c.85], §1111) | |
| A reaction: This argument is still significant in current philosophy of mind. If temperature is 'mean kinetic energy', you are left wondering where the energy came from, and why minds experience the heat. This is the 'Hard Question'. |
| 5955 | No one will ever find a city that lacks religious practices [Plutarch] |
| Full Idea: A city without holy places and gods, without any observance of prayers, oaths, oracles, sacrifices for blessings received or rites to avert evils, no traveller has ever seen or will ever see. | |
| From: Plutarch (74: Reply to Colotes [c.85], §1125) | |
| A reaction: The nearest you might get would be Soviet Moscow, but in 1973 I saw a man there jeering at a woman who was kneeling in the street outside a closed church. Plutarch would be stunned at the decline in religious practices in modern Europe. |