9 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. |
| 22329 | Logic is highly general truths abstracted from reality [Russell, by Glock] |
| Full Idea: In 1911 Russell held that the propositions of logic are supremely general truths about the most pervasive traits of reality, to which we have access by abstraction from non-logical propositions. | |
| From: report of Bertrand Russell (Philosophical Implications of Mathematical logic [1911]) by Hans-Johann Glock - What is Analytic Philosophy? 2.4 | |
| A reaction: Glock says the rival views were Mill's inductions, psychologism, and Frege's platonism. Wittgenstein converted Russell to a fifth view, that logic is empty tautologies. I remain resolutely attached to Russell's abstraction view. |
| 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. |
| 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. |
| 21569 | It is good to generalise truths as much as possible [Russell] |
| Full Idea: It is a good thing to generalise any truth as much as possible. | |
| From: Bertrand Russell (Philosophical Implications of Mathematical logic [1911], p.289) | |
| A reaction: An interesting claim, which seems to have a similar status to Ockham's Razor. Its best justification is pragmatic, and concerns strategies for coping with a big messy world. Russell's defence is in 'as much as possible'. |
| 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). |
| 22974 | Presentists lack the materials for a realist view of change [Price,H] |
| Full Idea: The presentist view seems to have lost the materials for a realist view of passage, change or temporal transition. | |
| From: Huw Price (The Flow of Time [2011], 2) | |
| A reaction: It is a nice point. How can a presentist talk of change if the only component that exists is the present time slice? Price says change can only be a kind of fiction for the presentist. Change in existence and in properties are distinct concepts. |
| 22973 | The present moment, time's direction, and time's dynamic quality seem to be objective facts [Price,H] |
| Full Idea: The flow of time seems to be an objective feature of reality because of 1) the present moment can be objectively distinguished, 2) time has an objective direction, of earlier and later, and 3) there is something objectively dynamic about time. | |
| From: Huw Price (The Flow of Time [2011], 1.1) | |
| A reaction: Price sets out to undermine all three of these claims, in implicit defence of a psychological view. I disagree with him. |
| 22975 | We must explain either the existence of a time direction, or our psychological sense of it [Price,H] |
| Full Idea: If the world comes equipped with a time orientation, where does it come from? If it doesn't, what explains our psychological feeling of a direction for time? | |
| From: Huw Price (The Flow of Time [2011], 3.5) | |
| A reaction: The chances of 'explaining' either one look slim to me. That is, the fact would explain our experience, but the experience without the fact looks ridiculous, and I cannot conceive of any time-free entity which could explain the fact. |