19 ideas
| 15970 | People generalise because it is easier to understand, and that is mistaken for deep philosophy [Feynman] |
| Full Idea: The topic of the laws of nature has a tendency to become too philosophical because it becomes too general, and a person talks in such generalities, that everybody can understand him. It is then considered to be some deep philosophy. | |
| From: Richard P. Feynman (The Character of Physical Law [1965], 1) | |
| A reaction: Feynman was famously anti-philosophical, but this is a good challenge. I like philosophy because I want to know broad general truths about my world, but I may just be gravitating towards what is easier. The challenge is to get true generalities. |
| 10688 | 'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall] |
| Full Idea: 'Equivocation' is when the terms do not mean the same thing in the premises and in the conclusion. | |
| From: JC Beall / G Restall (Logical Consequence [2005], Intro) |
| 10690 | Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall] |
| Full Idea: Logic is purely formal either when it is invariant under permutation of object (Tarski), or when it has totally abstracted away from all contents, or it is the constitutive norms for thought. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 2) | |
| A reaction: [compressed] The third account sounds rather woolly, and the second one sounds like a tricky operation, but the first one sounds clear and decisive, so I vote for Tarski. |
| 10691 | Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall] |
| Full Idea: Technical work on logical consequence has either focused on proofs, where validity is the existence of a proof of the conclusions from the premises, or on models, which focus on the absence of counterexamples. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 3) |
| 10695 | Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall] |
| Full Idea: Two different views of logical consequence are necessary truth-preservation (based on modelling possible worlds; favoured by Realists), or truth-preservation based on the meanings of the logical vocabulary (differing in various models; for Anti-Realists). | |
| From: JC Beall / G Restall (Logical Consequence [2005], 2) | |
| A reaction: Thus Dummett prefers the second view, because the law of excluded middle is optional. My instincts are with the first one. |
| 10689 | A step is a 'material consequence' if we need contents as well as form [Beall/Restall] |
| Full Idea: A logical step is a 'material consequence' and not a formal one, if we need the contents as well as the structure or form. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 2) |
| 10696 | A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall] |
| Full Idea: If a conclusion follows from an empty collection of premises, it is true by logic alone, and is a 'logical truth' (sometimes a 'tautology'), or, in the proof-centred approach, 'theorems'. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 4) | |
| A reaction: These truths are written as following from the empty set Φ. They are just implications derived from the axioms and the rules. |
| 10693 | Models are mathematical structures which interpret the non-logical primitives [Beall/Restall] |
| Full Idea: Models are abstract mathematical structures that provide possible interpretations for each of the non-logical primitives in a formal language. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 3) |
| 10692 | Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall] |
| Full Idea: There are many proof-systems, the main being Hilbert proofs (with simple rules and complex axioms), or natural deduction systems (with few axioms and many rules, and the rules constitute the meaning of the connectives). | |
| From: JC Beall / G Restall (Logical Consequence [2005], 3) |
| 21339 | We want the ontology of relations, not just a formal way of specifying them [Heil] |
| Full Idea: A satisfying account of relations must be ontologically serious. This means refusing to rest content with abstract specifications of relations as sets of ordered n-tuples. | |
| From: John Heil (Relations [2009], Intro) | |
| A reaction: A set of ordered entities would give the extension of a relation, which wouldn't, among other things, explain co-extensive relations (if all the people to my left were also taller than me). Heil's is a general cry from the heart about formal philosophy. |
| 21349 | Two people are indirectly related by height; the direct relation is internal, between properties [Heil] |
| Full Idea: If Simmias is taller than Socrates, they are indirectly related; they are related via their possession of properties that are themselves directly - and internally - related. Hence relational truths are made true by non-relational features of the world. | |
| From: John Heil (Relations [2009], 'Founding') | |
| A reaction: This seems to be a strategy for reducing external relations to internal relations, which are intrinsic to objects, which thus reduces the ontology. Heil is not endorsing it, but cites Kit Fine 2000. The germ of this idea is in Plato. |
| 21340 | Maybe all the other features of the world can be reduced to relations [Heil] |
| Full Idea: A striking idea is that relations are ontologically primary: monadic, non-relational features of the world are constituted by relations. A view of this kind is defended by Peirce, and contemporary 'structural realists' like Ladyman. | |
| From: John Heil (Relations [2009], 'Relational') | |
| A reaction: I can't make sense of this proposal, which seems to offer relations with no relata. What is a relation? What is it made of? How do you individuate two instances of a relations, without reference to the relata? |
| 21348 | In the case of 5 and 6, their relational truthmaker is just the numbers [Heil] |
| Full Idea: We might say that the truthmakers for 'six is greater than five' are six and five themselves. On this view, truthmakers for one class of relational truths are non-relational features of the world. | |
| From: John Heil (Relations [2009], 'Founding') | |
| A reaction: That seems to be a good way of expressing the existence of an internal relation. |
| 21351 | Truthmaking is a clear example of an internal relation [Heil] |
| Full Idea: Truthmaking is a paradigmatic internal relation: if you have a truthbearer, a representation, and you have the world as the truthbearer represents it as being, you have truthmaking, you have the truthbearer's being true. | |
| From: John Heil (Relations [2009], 'Causal') | |
| A reaction: It is nice to have an example of an internal relation other than numbers, and closer to the concrete world. Is the relation between the world and facts about the world the same thing, or another example? |
| 21344 | If R internally relates a and b, and you have a and b, you thereby have R [Heil] |
| Full Idea: A simple way to think about internal relations is: if R internally relates a and b, then, if you have a and b, you thereby have R. If you have six and you have five, you thereby have six's being greater than five. | |
| From: John Heil (Relations [2009], 'External') | |
| A reaction: This seems to work a lot better for abstracta than for physical objects, where I am struggling to think of a parallel example. Parenthood? Temporal relations between things? Acorn and oak? |
| 21350 | If properties are powers, then causal relations are internal relations [Heil] |
| Full Idea: On the conception that properties are powers, it is no longer obvious that causal relations are external relations. Given the powers - all the powers in play - you have the manifestations. | |
| From: John Heil (Relations [2009], 'Causal') | |
| A reaction: This also delivers on a plate the necessity felt to be in causal relations, because the relation is inevitable once you are given the relata. But can you have an accidental (rather than essential) internal relation? Not in the case of numbers. |
| 9410 | Physical Laws are rhythms and patterns in nature, revealed by analysis [Feynman] |
| Full Idea: There is a rhythm and a pattern between the phenomena of nature which is not apparent to the eye, but only to the eye of analysis; and it is these rhythms and patterns which we call Physical Laws. | |
| From: Richard P. Feynman (The Character of Physical Law [1965], Ch.1) |
| 18530 | Nobody understands quantum mechanics [Feynman] |
| Full Idea: I think I can safely say the nobody understands quantum mechanics. | |
| From: Richard P. Feynman (The Character of Physical Law [1965], 6) | |
| A reaction: It is really important that philosophers grasp this point! |
| 17707 | We should regard space as made up of many tiny pieces [Feynman, by Mares] |
| Full Idea: Feynman claims that we should regard space as made up of many tiny pieces, which have positive length, width and depth. | |
| From: report of Richard P. Feynman (The Character of Physical Law [1965], p.166) by Edwin D. Mares - A Priori 06.7 | |
| A reaction: The idea seems to be these are the minimum bits of space in which something can happen. |