16 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. |
| 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. |
| 13152 | We can talk of 'innumerable number', about the infinite points on a line [Newton] |
| Full Idea: If any man shall take the words number and sum in a larger sense, to understand things which are numberless and sumless (such as the infinite points on a line), I could allow him the contradictious phrase 'innumerable number' without absurdity. | |
| From: Isaac Newton (Letters to Bentley [1692], 1693.02.25) | |
| A reaction: [compressed] I take the key point here to be the phrase of taking number 'in a larger sense'. Like the word 'atom' in physics, the word 'number' retains its traditional reference, but has considerably shifted its scope. Amateurs must live with this. |
| 13151 | Not all infinites are equal [Newton] |
| Full Idea: It is an error that all infinites are equal. | |
| From: Isaac Newton (Letters to Bentley [1692], 1693.01.17) | |
| A reaction: There follows a discussion of the mathematicians' view of infinity. Cantor was not the first to notice that there is more than one sort of of infinity. |
| 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). |
| 2848 | Two people might agree in their emotional moral attitude while disagreeing in their judgement [Brink] |
| Full Idea: Critics of emotivism claim that moral agreement need not track agreement in attitude; moralists with the same attitude can disagree in their views, and they can hold the same view while disagreeing in attitude. | |
| From: David O. Brink (Emotivism [1995], p.224) | |
| A reaction: Thus two racists can disagree about how racists should behave. Sounds like a good criticism. |
| 2851 | Emotivists find it hard to analyse assertions of moral principles, rather than actual judgements [Brink] |
| Full Idea: It is hard for the emotivist to give an analysis of the occurrence of moral ideas in unasserted contexts, such as "IF he did wrong, then he should be punished". | |
| From: David O. Brink (Emotivism [1995], p.224) | |
| A reaction: This is the 'Frege-Geach Problem'. |
| 2853 | Emotivists claim to explain moral motivation by basing morality on non-cognitive attitudes [Brink] |
| Full Idea: By stressing the intimate connection between moral judgements and the agent's non-cognitive attitudes, emotivists claim to capture the motivational properties of moral judgement. | |
| From: David O. Brink (Emotivism [1995], p.223) | |
| A reaction: The same claim is made by contractarians, who start from our universal self-interest. Emotivists also nicely capture the motivation properties of immoral judgements. |
| 2852 | Emotivists tend to favour a redundancy theory of truth, making moral judgement meaningless [Brink] |
| Full Idea: If you want to recognise the truth of some moral judgements, perhaps to make room for the possibility of moral mistakes, then one may not be satisfied with the emotivists' tendency to appeal to the redundancy theory of truth. | |
| From: David O. Brink (Emotivism [1995], p.224) | |
| A reaction: Probably thinking of Simon Blackburn. People who adopt a redundancy view of truth for semantics are left floundering when discussing what is true in the rest of philosophy. |
| 2849 | Emotivism implies relativism about moral meanings, but critics say disagreements are about moral reference [Brink] |
| Full Idea: Emotivism suggests that different feelings lead to different individual meanings for moral terms, but critics say that meanings are the same, and disagreement is about the extension (range of reference) of the terms. | |
| From: David O. Brink (Emotivism [1995], p.224) | |
| A reaction: It's hard to see how 'ought to p' could have quite different meanings for an emotivist and (say) a theistic moralist. 'Ought' is an obvious and simple word. Good criticism. |
| 2850 | How can emotivists explain someone who recognises morality but is indifferent to it? [Brink] |
| Full Idea: It is not clear how the emotivist can accommodate the amoralist - one who recognises moral requirements but is indifferent to them. | |
| From: David O. Brink (Emotivism [1995], p.224) | |
| A reaction: Nietzsche recognised current morals, but was indifferent to them. It is hard to imagine, though, an amoralist who lacked all the feelings which imply morality. |
| 15863 | The principles of my treatise are designed to fit with a belief in God [Newton] |
| Full Idea: When I wrote my treatise about our system, I had an eye upon such principles as might work with considering men, for the belief of a deity. | |
| From: Isaac Newton (Letters to Bentley [1692], 1692.12.10) | |
| A reaction: Harré quotes this, and it shows that the rather passive view of nature Newton developed was to be supplemented by the active power of God. Without God, we need a more active view of nature. |
| 8340 | I do not pretend to know the cause of gravity [Newton] |
| Full Idea: You sometimes speak of gravity as essential and inherent in matter. Pray do no ascribe that notion to me; for the cause of gravity is what I do not pretend to know. | |
| From: Isaac Newton (Letters to Bentley [1692], 1693.01.17) | |
| A reaction: I take science to be a two-stage operation - first we discern the regularities, and then we explain them. Evolution was spotted, then explained by Darwin. Cancer from cigarettes was spotted, but hasn't been explained. Regularity is the beginning. |
| 13150 | The motions of the planets could only derive from an intelligent agent [Newton] |
| Full Idea: The motions which the planets now have could not spring from any natural cause alone, but were impressed by an intelligent agent. | |
| From: Isaac Newton (Letters to Bentley [1692], 1692.12.10) | |
| A reaction: He is writing to a cleric, but seems to be quite sincere about this. Elsewhere he just says he doesn't know what causes gravity. |
| 12178 | That gravity should be innate and essential to matter is absurd [Newton] |
| Full Idea: That gravity should be innate, inherent and essential to matter ...is to me so great an absurdity that I believe no man who has in philosophical matters a competent faculty of thinking can ever fall into it. | |
| From: Isaac Newton (Letters to Bentley [1692], 1693.02.25) | |
| A reaction: He is replying to some sermons, and he pays vague lip service to a possible divine force. Nevertheless, this is thoroughgoing anti-essentialism, and he talks of external 'laws' in the next sentence. Newton still sought the cause of gravity. |