16 ideas
| 18901 | Truthmakers are facts 'of' a domain, not something 'in' the domain [Sommers] |
| Full Idea: A fact is an existential characteristic 'of' the domain; it is not something 'in' the domain. To search for truth-making facts in the world is indeed futile. | |
| From: Fred Sommers (Intellectual Autobiography [2005], 'Existence') | |
| A reaction: Attacking Austin on truth. Helpful. It is hard to see how a physical object has a mysterious power to 'make' a truth. No energy-transfer seems involved in the making. Animals think true thoughts; I suspect that concerns their mental maps of the world. |
| 18904 | 'Predicable' terms come in charged pairs, with one the negation of the other [Sommers, by Engelbretsen] |
| Full Idea: Sommers took the 'predicable' terms of any language to come in logically charged pairs. Examples might be red/nonred, massive/massless, tied/untied, in the house/not in the house. The idea that terms can be negated was essential for such pairing. | |
| From: report of Fred Sommers (Intellectual Autobiography [2005]) by George Engelbretsen - Trees, Terms and Truth 2 | |
| A reaction: If, as Rumfitt says, we learn affirmation and negation as a single linguistic operation, this would fit well with it, though Rumfitt doubtless (as a fan of classical logic) prefers to negation sentences. |
| 18895 | Logic which maps ordinary reasoning must be transparent, and free of variables [Sommers] |
| Full Idea: What would a 'laws of thought' logic that cast light on natural language deductive thinking be like? Such a logic must be variable-free, conforming to normal syntax, and its modes of reasoning must be transparent, to make them virtually instantaneous. | |
| From: Fred Sommers (Intellectual Autobiography [2005], 'How We') | |
| A reaction: This is the main motivation for Fred Sommers's creation of modern term logic. Even if you are up to your neck in modern symbolic logic (which I'm not), you have to find this idea appealing. You can't leave it to the psychologists. |
| 18897 | Predicate logic has to spell out that its identity relation '=' is an equivalent relation [Sommers] |
| Full Idea: Because predicate logic contrues identities dyadically, its account of inferences involving identity propositions needs laws or axioms of identity, explicitly asserting that the dyadic realtion in 'x=y' possesses symmetry, reflexivity and transitivity. | |
| From: Fred Sommers (Intellectual Autobiography [2005], 'Syllogistic') |
| 18893 | Translating into quantificational idiom offers no clues as to how ordinary thinkers reason [Sommers] |
| Full Idea: Modern predicate logic's methods of justification, which involve translation into an artificial quantificational idiom, offer no clues to how the average person, knowing no logic and adhering to the vernacular, is so logically adept. | |
| From: Fred Sommers (Intellectual Autobiography [2005], Intro) | |
| A reaction: Of course, people are very logically adept when the argument is simple (because, I guess, they can test it against the world), but not at all good when the reasoning becomes more complex. We do, though, reason in ordinary natural language. |
| 7332 | There is a huge range of sentences of which we do not know the logical form [Davidson] |
| Full Idea: We do not know the logical form of sentences about counterfactuals, probabilities, causal relations, belief, perception, intention, purposeful action, imperatives, optatives, or interrogatives, or the role of adverbs, adjectives or mass terms. | |
| From: Donald Davidson (Truth and Meaning [1967], p.35) | |
| A reaction: [compressed] This is the famous 'Davidson programme', where teams of philosophers work out the logical forms for this lot, thus unravelling the logic of the world. If they are beavering away, some sort of overview should have emerged by now... |
| 18903 | Sommers promotes the old idea that negation basically refers to terms [Sommers, by Engelbretsen] |
| Full Idea: If there is one idea that is the keystone of the edifice that constitutes Sommers's united philosophy it is that terms are the linguistic entities subject to negation in the most basic sense. It is a very old idea, tending to be rejected in modern times. | |
| From: report of Fred Sommers (Intellectual Autobiography [2005]) by George Engelbretsen - Trees, Terms and Truth 2 | |
| A reaction: Negation in modern logic is an operator applied to sentences, typically writing '¬Fa', which denies that F is predicated of a, with Fa being an atomic sentence. Do we say 'not(Stan is happy)', or 'not-Stan is happy', or 'Stan is not-happy'? Third one? |
| 18894 | Predicates form a hierarchy, from the most general, down to names at the bottom [Sommers] |
| Full Idea: We organise our concepts of predicability on a hierarchical tree. At the top are terms like 'interesting', 'exists', 'talked about', which are predicable of anything. At the bottom are names, and in between are predicables of some things and not others. | |
| From: Fred Sommers (Intellectual Autobiography [2005], 'Category') | |
| A reaction: The heirarchy seem be arranged simply by the scope of the predicate. 'Tallest' is predicable of anything in principle, but only of a few things in practice. Is 'John Doe' a name? What is 'cosmic' predicable of? Challenging! |
| 18900 | Unfortunately for realists, modern logic cannot say that some fact exists [Sommers] |
| Full Idea: Unfortunately for the fate of realist philosophy, modern logic's treatment of 'exists' is resolutely inhospitable to facts as referents of phrases of the form 'the existence or non-existence of φ'. | |
| From: Fred Sommers (Intellectual Autobiography [2005], 'Realism') | |
| A reaction: Predicate logic has to talk about objects, and then attribute predicates to them. It tends to treat a fact as 'Fa' - this object has this predicate, but that's not really how we understand facts. |
| 18898 | In standard logic, names are the only way to refer [Sommers] |
| Full Idea: In modern predicate logic, definite reference by proper names is the primary and sole form of reference. | |
| From: Fred Sommers (Intellectual Autobiography [2005], 'Reference') | |
| A reaction: Hence we have to translate definite descriptions into (logical) names, or else paraphrase them out of existence. The domain only contains 'objects', so only names can uniquely pick them out. |
| 7772 | Compositionality explains how long sentences work, and truth conditions are the main compositional feature [Davidson, by Lycan] |
| Full Idea: Davidson's main argument in favour of his truth conditions theory of meaning is that compositionality is needed to account for our understanding of long, novel sentences, and a sentence's truth condition is its most obviously compositional feature. | |
| From: report of Donald Davidson (Truth and Meaning [1967]) by William Lycan - Philosophy of Language Ch.9 | |
| A reaction: This seems to me exactly right. As we hear a new long sentence unfold, we piece together the meaning. At the end we may spot that the meaning is silly, or an unverifiable speculation, or not what the speaker intended - but it is too late! It means. |
| 7327 | Davidson thinks Frege lacks an account of how words create sentence-meaning [Davidson, by Miller,A] |
| Full Idea: Davidson thinks that Frege's model for a theory of semantic value (and thereby for a systematic theory of sense) is unsatisfactory, because it provides no useful or explanatory account of how sentence-meaning can be a function of word-meaning. | |
| From: report of Donald Davidson (Truth and Meaning [1967]) by Alexander Miller - Philosophy of Language 8.1 | |
| A reaction: Put like that, it is not clear to me how you could even start to explain how word-meaning contributes to sentence meaning. Try speaking any sentence slowly, and observe how the sentence meaning builds up. Truth is, of course, relevant. |
| 7769 | You can state truth-conditions for "I am sick now" by relativising it to a speaker at a time [Davidson, by Lycan] |
| Full Idea: Davidson's response to the problem of how you would state truth conditions for "I am sick now" ...is to relativize its truth to a particular speaker and a time. | |
| From: report of Donald Davidson (Truth and Meaning [1967]) by William Lycan - Philosophy of Language Ch.9 | |
| A reaction: Lycan is not happy with this, but it seems a reasonable way to treat the truth of any statement containing indexicals. Never mind the 'truth conditions theory of meaning' - just ask whether "I am sick now" is true. |
| 6179 | Should we assume translation to define truth, or the other way around? [Blackburn on Davidson] |
| Full Idea: The concern of some philosophers has been expressed by saying that whereas Tarski took translation for granted, and sought to understand truth, Davidson takes truth for granted, and seeks to understand translation. | |
| From: comment on Donald Davidson (Truth and Meaning [1967]) by Simon Blackburn - Oxford Dictionary of Philosophy p.82 | |
| A reaction: We can just say that the two concepts are interdependent, but my personal intuitions side with Davidson. If you are going to take something as fundamental and axiomatic, truth looks a better bet than translation. |
| 13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
| Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
| From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
| A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
| 20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
| Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
| From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
| A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |