6 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. |
| 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. |
| 18398 | Space, time, and some other basics, are not causal powers [Ellis] |
| Full Idea: Spatial, temporal, and other primary properties and relationships are not causal powers. | |
| From: Brian Ellis (Response to David Armstrong [1999], p.42), quoted by David M. Armstrong - Truth and Truthmakers 10.4 | |
| A reaction: It is hard to see how time and space could actually be powers, but future results in physics (or even current results about 'fields') might change that. |
| 22063 | Effective individuals must posit a specific material body for themselves [Fichte] |
| Full Idea: Rational beings cannot posit themselves as effective individuals without ascribing to themselves a material body and determining it in doing so. | |
| From: Johann Fichte (The Science of Rights [1797], p.87), quoted by Ludwig Siep - Fichte | |
| A reaction: To be free entails a belief that one is 'effective', and a body is our only concept for that. This seems to be a transcendental proof that the body must exist, which is a neat inverted move! The Self sustains the body, for Fichte. |
| 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). |