11 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. |
| 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. |
| 21597 | Logical connectives have the highest precision, yet are infected by the vagueness of true and false [Russell, by Williamson] |
| Full Idea: Russell says the best chance of avoiding vagueness are the logical connectives. ...But the vagueness of 'true' and 'false' infects the logical connectives too. All words are vague. Russell concludes that all language is vague. | |
| From: report of Bertrand Russell (Vagueness [1923]) by Timothy Williamson - Vagueness 2.4 | |
| A reaction: This relies on the logical connectives being defined semantically, in terms of T and F, but that is standard. Presumably the formal uninterpreted syntax is not vague. |
| 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. |
| 9051 | Since natural language is not precise it cannot be in the province of logic [Russell, by Keefe/Smith] |
| Full Idea: Russell takes it that logic assumes precision, and since natural language is not precise it cannot be in the province of logic at all. | |
| From: report of Bertrand Russell (Vagueness [1923]) by R Keefe / P Smith - Intro: Theories of Vagueness §1 | |
| A reaction: I find this view congenial. It seems to me that the necessary prelude to logic is to do everything you can to eliminate ambiguity and vagueness from the sentences at issue. We want the proposition, or logical form. If there isn't one, forget it? |
| 9054 | Vagueness is only a characteristic of representations, such as language [Russell] |
| Full Idea: Vagueness and precision alike are characteristics which can only belong to a representation, of which language is an example. | |
| From: Bertrand Russell (Vagueness [1923], p.62) | |
| A reaction: Russell was the first to tackle the question of vagueness, and he may have got it right. If we are unable to decide which set an object belongs in (red or orange) that is a problem for our conceptual/linguistic scheme. The object still has a colour! |
| 9295 | Not only substances have attributes; events, actions, states and qualities can have them [Teichmann] |
| Full Idea: It is not true that only substances have attributes; events, actions, states and qualities can all be characterized. | |
| From: Jenny Teichmann (The Mind and the Soul [1974], Ch.2) | |
| A reaction: This is why it is so important to distinguish the actual properties in nature from those that can be fancifully hypothesized by a linguistic being. Is there any limit to the possible number of levels of meta-properties? |
| 9293 | Body-spirit interaction ought to result in losses and increases of energy in the material world [Teichmann] |
| Full Idea: Since the interaction of bodies themselves involves energy-flow, it looks as if interaction between body and spirit ought to result in losses and increases of energy in the material world. | |
| From: Jenny Teichmann (The Mind and the Soul [1974], Ch.2) | |
| A reaction: A nice statement of an important argument. It forces the dualist to go the whole way, asserting that not only is the mind immaterial, but that it can be active without energy, and cover its traces in the physical world. Doesn't look good. |
| 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). |
| 9292 | The Soul has no particular capacity (in the way thinking belongs to the mind) [Teichmann] |
| Full Idea: On the whole, the Soul has no capacities which belong to it pre-eminently in the way that thinking 'belongs' to the mind. | |
| From: Jenny Teichmann (The Mind and the Soul [1974], Ch.1) | |
| A reaction: There are no phenomena which have to be saved by postulating a soul. It lacks a function within a human being, but it has a crucial function within a large theological picture. |
| 9294 | No individuating marks distinguish between Souls [Teichmann] |
| Full Idea: There are no individuating marks which could serve to differentiate one Soul from another. | |
| From: Jenny Teichmann (The Mind and the Soul [1974], Ch.2) | |
| A reaction: Presumably they could have at least much identity as two different electrons (if they are in space-time?). It is hard to see why anyone would be interested in their 'own' immortality, if loss of all individuality was a condition. |