15 ideas
14187 | If logic is topic-neutral that means it delves into all subjects, rather than having a pure subject matter [Read] |
Full Idea: The topic-neutrality of logic need not mean there is a pure subject matter for logic; rather, that the logician may need to go everywhere, into mathematics and even into metaphysics. | |
From: Stephen Read (Formal and Material Consequence [1994], 'Logic') |
14183 | Maybe arguments are only valid when suppressed premises are all stated - but why? [Read] |
Full Idea: Maybe some arguments are really only valid when a suppressed premise is made explicit, as when we say that 'taller than' is a transitive concept. ...But what is added by making the hidden premise explicit? It cannot alter the soundness of the argument. | |
From: Stephen Read (Formal and Material Consequence [1994], 'Suppress') |
14188 | Not all arguments are valid because of form; validity is just true premises and false conclusion being impossible [Read] |
Full Idea: Belief that every valid argument is valid in virtue of form is a myth. ..Validity is a question of the impossibility of true premises and false conclusion for whatever reason, and some arguments are materially valid and the reason is not purely logical. | |
From: Stephen Read (Formal and Material Consequence [1994], 'Logic') | |
A reaction: An example of a non-logical reason is the transitive nature of 'taller than'. Conceptual connections are the usual example, as in 'it's red so it is coloured'. This seems to be a defence of the priority of semantic consequence in logic. |
14182 | If the logic of 'taller of' rests just on meaning, then logic may be the study of merely formal consequence [Read] |
Full Idea: In 'A is taller than B, and B is taller than C, so A is taller than C' this can been seen as a matter of meaning - it is part of the meaning of 'taller' that it is transitive, but not of logic. Logic is now seen as the study of formal consequence. | |
From: Stephen Read (Formal and Material Consequence [1994], 'Reduct') | |
A reaction: I think I find this approach quite appealing. Obviously you can reason about taller-than relations, by putting the concepts together like jigsaw pieces, but I tend to think of logic as something which is necessarily implementable on a machine. |
14184 | In modus ponens the 'if-then' premise contributes nothing if the conclusion follows anyway [Read] |
Full Idea: A puzzle about modus ponens is that the major premise is either false or unnecessary: A, If A then B / so B. If the major premise is true, then B follows from A, so the major premise is redundant. So it is false or not needed, and contributes nothing. | |
From: Stephen Read (Formal and Material Consequence [1994], 'Repres') | |
A reaction: Not sure which is the 'major premise' here, but it seems to be saying that the 'if A then B' is redundant. If I say 'it's raining so the grass is wet', it seems pointless to slip in the middle the remark that rain implies wet grass. Good point. |
14186 | Logical connectives contain no information, but just record combination relations between facts [Read] |
Full Idea: The logical connectives are useful for bundling information, that B follows from A, or that one of A or B is true. ..They import no information of their own, but serve to record combinations of other facts. | |
From: Stephen Read (Formal and Material Consequence [1994], 'Repres') | |
A reaction: Anyone who suggests a link between logic and 'facts' gets my vote, so this sounds a promising idea. However, logical truths have a high degree of generality, which seems somehow above the 'facts'. |
14185 | Conditionals are just a shorthand for some proof, leaving out the details [Read] |
Full Idea: Truth enables us to carry various reports around under certain descriptions ('what Iain said') without all the bothersome detail. Similarly, conditionals enable us to transmit a record of proof without its detail. | |
From: Stephen Read (Formal and Material Consequence [1994], 'Repres') | |
A reaction: This is his proposed Redundancy Theory of conditionals. It grows out of the problem with Modus Ponens mentioned in Idea 14184. To say that there is always an implied 'proof' seems a large claim. |
7544 | Many people imagine that to experience is to understand [Goethe] |
Full Idea: There are many people who imagine that what they experience they also understand. | |
From: Wolfgang von Goethe (Maxims and Reflections [1825], 889) | |
A reaction: This should be posted over the arrivals gate of every international airport, for returning holiday-makers. It seems to place Goethe on the rationalist side of the debate with empiricism. It is hard to explain 'understanding' in Humean terms. |
7541 | Man never understands how anthropomorphic he is [Goethe] |
Full Idea: Man never understands how anthropomorphic he is. | |
From: Wolfgang von Goethe (Maxims and Reflections [1825], 203) | |
A reaction: Nice. It is true, even when it is pointed out to us. No matter how hard we try to realise how very different animals are from us, we can't help identifying with them. Religious people even do it with inanimate creation. |
7543 | We gain self-knowledge through action, not thought - especially when doing our duty [Goethe] |
Full Idea: How can we learn self-knowledge? Never by taking thought, but rather by action. Try to do your duty and you'll soon discover what you're like. | |
From: Wolfgang von Goethe (Maxims and Reflections [1825], 442) | |
A reaction: Good! I even like the unfashionable bit about duty. If you just do what you want, you will discover your interests, but not so much about your capacities. However, when you have to do something less comfortable, it is very revealing. |
7540 | Beauty is a manifestation of secret natural laws [Goethe] |
Full Idea: Beauty is a manifestation of secret natural laws which without this appearance would have remained eternally hidden from us. | |
From: Wolfgang von Goethe (Maxims and Reflections [1825], 183) | |
A reaction: An interesting defence of beauty as an objective feature of the world. I'm not sure. Much beauty is indeed the result of growth or erosion expressing underlying laws, but then I have always thought there was a sexual component to visual beauty. |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |
7538 | The happiest people link the beginning and end of life [Goethe] |
Full Idea: The happiest man is one who can link the end of his life with its beginning. | |
From: Wolfgang von Goethe (Maxims and Reflections [1825], 140) | |
A reaction: [from 'Art and Antiquity']. A nice thought, which chimes in with the idea that a good life is like a complete story or a work of art (Idea 7501), or that it is 'eudaimon'. |
7542 | The best form of government teaches us to govern ourselves [Goethe] |
Full Idea: You ask which form of government is the best? Whichever teaches us to govern ourselves. | |
From: Wolfgang von Goethe (Maxims and Reflections [1825], 353) | |
A reaction: Not a fashionable view, since the rise of freedom as the highest political ideal, but I identify with the idea that a good government should educate, and should try to facilitate virtue as well as pleasure. |
7539 | To get duties from people without rights, you must pay them well [Goethe] |
Full Idea: If you demand duties from people and will not concede them rights, you have to pay them well. | |
From: Wolfgang von Goethe (Maxims and Reflections [1825], 180) | |
A reaction: [from 'Art and Antiquity']. ...or have great power over them. Goethe gives the optimistic liberal view, rather than the Marxist view. |