8 ideas
| 18812 | Split out the logical vocabulary, make an assignment to the rest. It's logical if premises and conclusion match [Tarski, by Rumfitt] |
| Full Idea: Tarski made a division of logical and non-logical vocabulary. He then defined a model as a non-logical assignment satisfying the corresponding sentential function. Then a conclusion follows logically if every model of the premises models the conclusion. | |
| From: report of Alfred Tarski (The Concept of Logical Consequence [1936]) by Ian Rumfitt - The Boundary Stones of Thought 3.2 | |
| A reaction: [compressed] This is Tarski's account of logical consequence, which follows on from his account of truth. 'Logical validity' is then 'true in every model'. Rumfitt doubts whether Tarski has given the meaning of 'logical consequence'. |
| 13344 | X follows from sentences K iff every model of K also models X [Tarski] |
| Full Idea: The sentence X follows logically from the sentences of the class K if and only if every model of the class K is also a model of the sentence X. | |
| From: Alfred Tarski (The Concept of Logical Consequence [1936], p.417) | |
| A reaction: [see Idea 13343 for his account of a 'model'] He is offering to define logical consequence in general, but this definition fits what we now call 'semantic consequence', written |=. This it is standard practice to read |= as 'models'. |
| 13343 | A 'model' is a sequence of objects which satisfies a complete set of sentential functions [Tarski] |
| Full Idea: An arbitrary sequence of objects which satisfies every sentential function of the sentences L' will be called a 'model' or realization of the class L of sentences. There can also be a model of a single sentence is this way. | |
| From: Alfred Tarski (The Concept of Logical Consequence [1936], p.417) | |
| A reaction: [L' is L with the constants replaced by variables] Tarski is the originator of model theory, which is central to modern logic. The word 'realization' is a helpful indicator of what he has in mind. A model begins to look like a possible world. |
| 13345 | Sentences are 'analytical' if every sequence of objects models them [Tarski] |
| Full Idea: A class of sentences can be called 'analytical' if every sequence of objects is a model of it. | |
| From: Alfred Tarski (The Concept of Logical Consequence [1936], p.418) | |
| A reaction: See Idea 13344 and Idea 13343 for the context of this assertion. |
| 15675 | We don't condemn people for being bad at reasoning [Finlayson] |
| Full Idea: We do not morally disapprove of people who are incompetent reasoners. | |
| From: James Gordon Finlayson (Habermas [2005], Ch.6:83) | |
| A reaction: Well, we don't morally disapprove simply of their lack of reasoning ability, but we may morally disapprove of their actions, which have arisen entirely from the disability. |
| 6017 | Nomos is king [Pindar] |
| Full Idea: Nomos is king. | |
| From: Pindar (poems [c.478 BCE], S 169), quoted by Thomas Nagel - The Philosophical Culture | |
| A reaction: This seems to be the earliest recorded shot in the nomos-physis wars (the debate among sophists about moral relativism). It sounds as if it carries the full relativist burden - that all that matters is what has been locally decreed. |
| 15674 | One can universalise good advice, but that doesn't make it an obligation [Finlayson] |
| Full Idea: 'Early to bed and early to rise' is a universalizable maxim, but, though it might be good advice, there is obviously no such obligation. | |
| From: James Gordon Finlayson (Habermas [2005], Ch.6:83) | |
| A reaction: I take it that Kant's rule won't distinguish moral guidance from prudential guidance. Unfair, I think. I may be a lark, but when I universalise this maxim I see that it can't be willed as a universal rule, because we should tolerate the owls. |
| 15662 | The 'culture industry' is an advertisement for the way things are [Finlayson] |
| Full Idea: Critical theory said that culture unwittingly played the role of an advertisement for the way things are. Horkheimer and Adorno referred to this phenomenon as the 'culture industry'. | |
| From: James Gordon Finlayson (Habermas [2005], Ch.1:04) | |
| A reaction: An interesting perspective. However, absolutely everything is an advertisement for what it offers. I think this is especially true of moral (and immoral) actions. |