13 ideas
| 13342 | Carnap defined consequence by contradiction, but this is unintuitive and changes with substitution [Tarski on Carnap] |
| Full Idea: Carnap proposed to define consequence as 'sentence X follows from the sentences K iff the sentences K and the negation of X are contradictory', but 1) this is intuitively impossible, and 2) consequence would be changed by substituting objects. | |
| From: comment on Rudolph Carnap (The Logical Syntax of Language [1934], p.88-) by Alfred Tarski - The Concept of Logical Consequence p.414 | |
| A reaction: This seems to be the first step in the ongoing explicit discussion of the nature of logical consequence, which is now seen by many as the central concept of logic. Tarski brings his new tool of 'satisfaction' to bear. |
| 13251 | Each person is free to build their own logic, just by specifying a syntax [Carnap] |
| Full Idea: In logic, there are no morals. Everyone is at liberty to build his own logic, i.e. his own form of language. All that is required is that he must state his methods clearly, and give syntactical rules instead of philosophical arguments. | |
| From: Rudolph Carnap (The Logical Syntax of Language [1934], §17), quoted by JC Beall / G Restall - Logical Pluralism 7.3 | |
| A reaction: This is understandable, but strikes me as close to daft relativism. If I specify a silly logic, I presume its silliness will be obvious. By what criteria? I say the world dictates the true logic, but this is a minority view. |
| 8463 | Maths can be reduced to logic and set theory [Quine] |
| Full Idea: Researches in the foundations of mathematics have made it clear that all of (interpreted) mathematics can be got down to logic and set theory, and the objects needed for mathematics can be got down to the category of classes (and classes of classes..). | |
| From: Willard Quine (The Scope and Language of Science [1954], §VI) | |
| A reaction: This I take to be a retreat from pure logicism, presumably influenced by Gödel. So can set theory be reduced to logic? Crispin Wright is the one the study. |
| 8461 | The category of objects incorporates the old distinction of substances and their modes [Quine] |
| Full Idea: The category of objects embraces indiscriminately what would anciently have been distinguished as substances and as modes or states of substances. | |
| From: Willard Quine (The Scope and Language of Science [1954], §6) | |
| A reaction: This nicely captures Quine's elimination of properties, by presenting them as inseparable from their objects/substances. Armstrong calls this 'Ostrich Nominalism' (for refusing to address the universals problem) but Quineans are unshaken. |
| 8462 | A hallucination can, like an ague, be identified with its host; the ontology is physical, the idiom mental [Quine] |
| Full Idea: A physical ontology has a place for states of mind. An inspiration or a hallucination can, like the fit of ague, be identified with its host for the duration. It leaves our mentalistic idioms fairly intact, but reconciles them with a physical ontology. | |
| From: Willard Quine (The Scope and Language of Science [1954], §VI) | |
| A reaction: Quine is employing the same strategy that he uses for substances and properties (Idea 8461): take the predication as basic, rather than reifying the thing being predicated. The ague analogy suggests that Quine is an incipient functionalist. |
| 3282 | The general form of moral reasoning is putting yourself in other people's shoes [Nagel] |
| Full Idea: I believe the general form of moral reasoning is to put yourself in other people's shoes. | |
| From: Thomas Nagel (Equality [1977], §9) |
| 3278 | An egalitarian system must give priority to those with the worst prospects in life [Nagel] |
| Full Idea: What makes a system egalitarian is the priority it gives to the claims of those whose overall life prospects put them at the bottom. | |
| From: Thomas Nagel (Equality [1977], §6) |
| 3275 | Equality was once opposed to aristocracy, but now it opposes public utility and individual rights [Nagel] |
| Full Idea: Egalitarianism was once opposed to aristocratic values, but now it is opposed by adherents of two non-aristocratic values: utility (increase benefit, even if unequally) and individual rights (which redistribution violates). | |
| From: Thomas Nagel (Equality [1977], §2) |
| 3281 | The ideal of acceptability to each individual underlies the appeal to equality [Nagel] |
| Full Idea: The ideal of acceptability to each individual underlies the appeal to equality. | |
| From: Thomas Nagel (Equality [1977], §8) |
| 3277 | In judging disputes, should we use one standard, or those of each individual? [Nagel] |
| Full Idea: In assessing equality of claims, it must be decided whether to use a single, objective standard, or whether interests should be ranked by the person's own estimation. Also should they balance momentary or long-term needs? | |
| From: Thomas Nagel (Equality [1977], §6) |
| 3274 | Equality can either be defended as good for society, or as good for individual rights [Nagel] |
| Full Idea: The communitarian defence of equality says it is good for society as a whole, whereas the individualistic defence defends equality as a correct distributive principle. | |
| From: Thomas Nagel (Equality [1977], §2) |
| 3273 | Equality nowadays is seen as political, social, legal and economic [Nagel] |
| Full Idea: Contemporary political debate recognises four types of equality: political, social, legal and economic. | |
| From: Thomas Nagel (Equality [1977], §1) | |
| A reaction: Meaning equality of 1) power and influence, 2) status and respect, 3) rights and justice, 4) wealth. |
| 3276 | A morality of rights is very minimal, leaving a lot of human life without restrictions or duties [Nagel] |
| Full Idea: The morality of rights tends to be a limited, even minimal, morality. It leaves a great deal of human life ungoverned by moral restrictions or requirements. | |
| From: Thomas Nagel (Equality [1977], §5) |