15 ideas
| 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) |
| 7746 | We don't normally think of names as having senses (e.g. we don't give definitions of them) [Searle] |
| Full Idea: If Tully=Cicero is synthetic, the names must have different senses, which seems implausible, for we don't normally think of proper names as having senses in the way that predicates do (we do not, e.g., give definitions of proper names). | |
| From: John Searle (Proper Names [1958], p.89) | |
| A reaction: It is probably necessary to prize apart the question of whether Tully 'has' (intrinsically) a sense, from whether we think of Tully in that way. Stacks of books have appeared about this one, since Kripke. |
| 7747 | How can a proper name be correlated with its object if it hasn't got a sense? [Searle] |
| Full Idea: It seems that a proper name could not have a reference unless it did have a sense, for how, unless the name has a sense, is it to be correlated with the object? | |
| From: John Searle (Proper Names [1958], p.91) | |
| A reaction: This might (just) be the most important question ever asked in modern philosophy, since it provoked Kripke into answering it, by giving a social, causal, externalist account of how names (and hence lots of language) actually work. But Searle has a point. |
| 7748 | 'Aristotle' means more than just 'an object that was christened "Aristotle"' [Searle] |
| Full Idea: Aristotle being identical with an object that was originally christened will not suffice, for the force of "Aristotle" is greater than the force of 'identical with an object named "Aristotle"', for not just any object named "Aristotle" will do. | |
| From: John Searle (Proper Names [1958], p.93) | |
| A reaction: This anticipates Kripke's proposal to base reference on baptism. I remain unsure about how rigid a designation of Aristotle could be, in a possible world where his father died young, and he became an illiterate soldier who hates philosophy. |
| 7749 | Reference for proper names presupposes a set of uniquely referring descriptions [Searle] |
| Full Idea: To use a proper name referringly is to presuppose the truth of certain uniquely referring descriptive statements. ...Names are pegs on which to hang descriptions. | |
| From: John Searle (Proper Names [1958], p.94) | |
| A reaction: This 'cluster' view of Searle's has become notorious, but I think one could at least try to mount a defence. The objection to Searle is that none of the descriptions are necessary, unlike just being the named object. |
| 7750 | Proper names are logically connected with their characteristics, in a loose way [Searle] |
| Full Idea: If asked whether or not proper names are logically connected with characteristics of the object to which they refer, the answer is 'yes, in a loose sort of way'. | |
| From: John Searle (Proper Names [1958], p.96) | |
| A reaction: It seems to be inviting trouble to assert that a connection is both 'logical' and 'loose'. Clearly Searle has been reading too much later Wittgenstein. This is probably the weakest point in Searle's proposal, which brought a landslide of criticism. |
| 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) |
| 3570 | Maybe knowledge is belief which 'tracks' the truth [Nozick, by Williams,M] |
| Full Idea: Nozick suggests that knowledge is just belief which 'tracks the truth' (hence leaving out justification). | |
| From: report of Robert Nozick (Philosophical Explanations [1981]) by Michael Williams - Problems of Knowledge Ch. 2 |
| 2748 | A true belief isn't knowledge if it would be believed even if false. It should 'track the truth' [Nozick, by Dancy,J] |
| Full Idea: Nozick says Gettier cases aren't knowledge because the proposition would be believed even if false. Proper justification must be more sensitive to the truth ("track the truth"). | |
| From: report of Robert Nozick (Philosophical Explanations [1981], 3.1) by Jonathan Dancy - Intro to Contemporary Epistemology 3.1 | |
| A reaction: This is a bad idea. I see a genuine tree in my garden and believe it is there, so I know it. That I might have believed it if I was in virtually reality, or observing a mirror, won't alter that. |