18 ideas
| 11211 | If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt] |
| Full Idea: If a designated conclusion follows from the premisses, but the argument involves two howlers which cancel each other out, then the moral is that the path an argument takes from premisses to conclusion does matter to its logical evaluation. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], II) | |
| A reaction: The drift of this is that our view of logic should be a little closer to the reasoning of ordinary language, and we should rely a little less on purely formal accounts. |
| 10794 | The nominalist is tied by standard semantics to first-order, denying higher-order abstracta [Marcus (Barcan)] |
| Full Idea: The nominalist finds that standard semantics shackles him to first-order languages if, as nominalists are wont, he is to make do without abstract higher order objects. | |
| From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.166) | |
| A reaction: Aha! Since I am pursuing a generally nominalist strategy in metaphysics, I suddenly see that I must adopt a hostile attitude to higher-order logic! Maybe plural quantification is the way to go, with just first-order objects. |
| 11210 | Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt] |
| Full Idea: If 'and' and 'but' really are alike in sense, in what might that likeness consist? Some philosophers of classical logic will reply that they share a sense by virtue of sharing a truth table. | |
| From: Ian Rumfitt ("Yes" and "No" [2000]) | |
| A reaction: This is the standard view which Rumfitt sets out to challenge. |
| 11212 | The sense of a connective comes from primitively obvious rules of inference [Rumfitt] |
| Full Idea: A connective will possess the sense that it has by virtue of its competent users' finding certain rules of inference involving it to be primitively obvious. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], III) | |
| A reaction: Rumfitt cites Peacocke as endorsing this view, which characterises the logical connectives by their rules of usage rather than by their pure semantic value. |
| 10786 | Anything which refers tends to be called a 'name', even if it isn't a noun [Marcus (Barcan)] |
| Full Idea: The tendency has been to call any expression a 'name', however distant from the grammatical category of nouns, provided it is seen as referring. | |
| From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.162) |
| 10788 | Nominalists see proper names as a main vehicle of reference [Marcus (Barcan)] |
| Full Idea: For a nominalist with an ontology of empirically distinguishable objects, proper names are seen as a primary vehicle of reference. | |
| From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.162) |
| 10799 | Nominalists should quantify existentially at first-order, and substitutionally when higher [Marcus (Barcan)] |
| Full Idea: For the nominalist, at level zero, where substituends are referring names, the quantifiers may be read existentially. Beyond level zero, the variables and quantifiers are read sustitutionally (though it is unclear whether this program is feasible). | |
| From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.167) |
| 10790 | Quantifiers are needed to refer to infinitely many objects [Marcus (Barcan)] |
| Full Idea: An adequate language for referring to infinitely many objects would seem to require variables and quantifiers in addition to names. | |
| From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.164) |
| 10791 | Substitutional semantics has no domain of objects, but place-markers for substitutions [Marcus (Barcan)] |
| Full Idea: On a substitutional semantics of a first-order language, a domain of objects is not specified. Variables do not range over objects. They are place markers for substituends (..and sentences are true-for-all-names, or true-for-at-least-one-name). | |
| From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.165) |
| 10785 | Maybe a substitutional semantics for quantification lends itself to nominalism [Marcus (Barcan)] |
| Full Idea: It has been suggested that a substitutional semantics for quantification theory lends itself to nominalistic aims. | |
| From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.161) |
| 10795 | Substitutional language has no ontology, and is just a way of speaking [Marcus (Barcan)] |
| Full Idea: Translation into a substitutional language does not force the ontology. It remains, literally, and until the case for reference can be made, a façon de parler. That is the way the nominalist would like to keep it. | |
| From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.166) |
| 10798 | A true universal sentence might be substitutionally refuted, by an unnamed denumerable object [Marcus (Barcan)] |
| Full Idea: Critics say if there are nondenumerably many objects, then on the substitutional view there might be true universal sentences falsified by an unnamed object, and there must always be some such, for names are denumerable. | |
| From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.167) | |
| A reaction: [See Quine 'Reply to Prof. Marcus' p.183] The problem seems to be that there would be names which are theoretically denumerable, but not nameable, and hence not available for substitution. Marcus rejects this, citing compactness. |
| 10787 | Is being just referent of the verb 'to be'? [Marcus (Barcan)] |
| Full Idea: Being itself has been viewed as referent of the verb 'to be'. | |
| From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.162) |
| 10789 | Nominalists say predication is relations between individuals, or deny that it refers [Marcus (Barcan)] |
| Full Idea: Nominalists have the major task of explaining how predicates work. They usually construct it as a relation between individuals, or deny the referential function of predicates. | |
| From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.163) |
| 10796 | If objects are thoughts, aren't we back to psychologism? [Marcus (Barcan)] |
| Full Idea: If objects are thoughts, aren't we back to psychologism? | |
| From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.166) | |
| A reaction: Personally I don't think that would be the end of the world, but Fregeans go into paroxyms at the mention of 'psychology', because they fear that it destroys objectivity. That may be because they haven't understood thought properly. |
| 10797 | Substitutivity won't fix identity, because expressions may be substitutable, but not refer at all [Marcus (Barcan)] |
| Full Idea: Substitutivity 'salve veritate' cannot define identity since two expressions may be everywhere intersubstitutable and not refer at all. | |
| From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.167) |
| 11214 | We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt] |
| Full Idea: The standard view is that affirming not-A is more complex than affirming the atomic sentence A itself, with the latter determining its sense. But we could learn 'not' directly, by learning at once how to either affirm A or reject A. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], IV) | |
| A reaction: [compressed] This seems fairly anti-Fregean in spirit, because it looks at the psychology of how we learn 'not' as a way of clarifying what we mean by it, rather than just looking at its logical behaviour (and thus giving it a secondary role). |
| 7607 | Nagarjuna and others pronounced the world of experience to be an illusion [Nagarjuna, by Armstrong,K] |
| Full Idea: Many later Buddhists (after Nagarjuna, c.120 CE) developed a belief that everything we experience is an illusion: in the West we would call them idealists. | |
| From: report of Nagarjuna (teachings [c.120]) by Karen Armstrong - A History of God Ch.3 | |
| A reaction: This is just one step beyond Plato (who at least hung onto the immediate world as an inferior reality), and is presumably intended to motivate meditators to break out of the misery of existence into a higher realm. Personally I am against it. |