39 ideas
| 13939 | No possible evidence could decide the reality of numbers, so it is a pseudo-question [Carnap] |
| Full Idea: I cannot think of any possible evidence that would be regarded as relevant by both nominalists and realists about numbers, and would decide the controversy, or make one side more probable. Hence I regard the external questions as pseudo-questions. | |
| From: Rudolph Carnap (Empiricism, Semantics and Ontology [1950], 4) |
| 16252 | Metaphysics uses empty words, or just produces pseudo-statements [Carnap] |
| Full Idea: Since metaphysics doesn't want to assert analytic propositions, nor fall within the domain of physical science, it is compelled to employ words for which no criteria of application are specified, ..or else combine meaningful words..into pseudo-statements. | |
| From: Rudolph Carnap (Elimination of Metaphysics by Analysis of Language [1959]), quoted by Tim Maudlin - The Metaphysics within Physics 2.4 | |
| A reaction: A classic summary of the logical positivist rejection of metaphysics. I incline to treat metaphysics as within the domain of science, but at a level of generality so high that practising scientists become bewildered and give up. |
| 17596 | Coherence problems have positive and negative restraints; solutions maximise constraint satisfaction [Thagard] |
| Full Idea: A coherence problem is a set of elements connected by positive and negative restraints, and a solution consists of partitioning the elements into two sets (accepted and rejected) in a way that maximises satisfaction of the constraints. | |
| From: Paul Thagard (Coherence: The Price is Right [2012], p.42) | |
| A reaction: I'm enthusiastic about this, as it begins to clarify the central activity of epistemology, which is the quest for best explanations. |
| 17597 | Coherence is explanatory, deductive, conceptual, analogical, perceptual, and deliberative [Thagard] |
| Full Idea: I propose that there are six main kinds of coherence: explanatory, deductive, conceptual, analogical, perceptual, and deliberative. ...Epistemic coherence is a combination of the first five kinds, and ethics adds the sixth. | |
| From: Paul Thagard (Coherence: The Price is Right [2012], p.43) | |
| A reaction: Wonderful. Someone is getting to grips with the concept of coherence, instead of just whingeing about how vague it is. |
| 17598 | Explanatory coherence needs symmetry,explanation,analogy,data priority, contradiction,competition,acceptance [Thagard] |
| Full Idea: Informally, a theory of explanatory coherence has the principles of symmetry, explanation, analogy, data priority, contradiction, competition and acceptance. | |
| From: Paul Thagard (Coherence: The Price is Right [2012], p.44) | |
| A reaction: [Thagard give a concise summary of his theory here] Again Thagard makes a wonderful contribution in an area where most thinkers are pessimistic about making any progress. His principles are very plausible. |
| 1403 | A rational donkey would starve to death between two totally identical piles of hay [Buridan, by PG] |
| Full Idea: A rational donkey faced with two totally identical piles of hay would be unable to decide which one to eat first, and would therefore starve to death | |
| From: report of Jean Buridan (talk [1338]) by PG - Db (ideas) | |
| A reaction: also De Caelo 295b32 (Idea 19740). |
| 17602 | Verisimilitude comes from including more phenomena, and revealing what underlies [Thagard] |
| Full Idea: A scientific theory is progressively approximating the truth if it increases its explanatory coherence by broadening to more phenomena and deepening by investigating layers of mechanisms. | |
| From: Paul Thagard (Coherence: The Price is Right [2012], p.46) |
| 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. |
| 13936 | Questions about numbers are answered by analysis, and are analytic, and hence logically true [Carnap] |
| Full Idea: For the internal question like 'is there a prime number greater than a hundred?' the answers are found by logical analysis based on the rules for the new expressions. The answers here are analytic, i.e., logically true. | |
| From: Rudolph Carnap (Empiricism, Semantics and Ontology [1950], 2) |
| 8748 | Logical positivists incorporated geometry into logicism, saying axioms are just definitions [Carnap, by Shapiro] |
| Full Idea: The logical positivists brought geometry into the fold of logicism. The axioms of, say, Euclidean geometry are simply definitions of primitive terms like 'point' and 'line'. | |
| From: report of Rudolph Carnap (Empiricism, Semantics and Ontology [1950]) by Stewart Shapiro - Thinking About Mathematics 5.3 | |
| A reaction: If the concept of 'line' is actually created by its definition, then we need to know exactly what (say) 'shortest' means. If we are merely describing a line, then our definition can be 'impredicative', using other accepted concepts. |
| 8960 | Internal questions about abstractions are trivial, and external ones deeply problematic [Carnap, by Szabó] |
| Full Idea: Carnap's verdict is that questions regarding the existence of abstracta tend to be trivial when taken as internal and deeply problematic when taken as external. | |
| From: report of Rudolph Carnap (Empiricism, Semantics and Ontology [1950]) by Zoltán Gendler Szabó - Nominalism 6 | |
| A reaction: If the internal aspect of the problem is 'trivial', this would put Carnap in league with fictionalists, who are only committed to entities while playing the current game. What is the status of the theory? Carnap wanted flowers to bloom. |
| 13933 | Existence questions are 'internal' (within a framework) or 'external' (concerning the whole framework) [Carnap] |
| Full Idea: We distinguish two kinds of existence questions: first, entities of a new kind within the framework; we call them 'internal questions'. Second, 'external questions', concerning the existence or reality of the system of entities as a whole. | |
| From: Rudolph Carnap (Empiricism, Semantics and Ontology [1950], 2) | |
| A reaction: This nicely disposes of many ontological difficulties, but at the price of labelling most external questions as meaningless, so that the internal answers have very little commitment, and the external (big) questions are now banned. Not for me. |
| 13934 | To be 'real' is to be an element of a system, so we cannot ask reality questions about the system itself [Carnap] |
| Full Idea: To be real in the scientific sense means to be an element of the system; hence this concept cannot be meaningfully applied to the system itself. | |
| From: Rudolph Carnap (Empiricism, Semantics and Ontology [1950], 2) |
| 13938 | A linguistic framework involves commitment to entities, so only commitment to the framework is in question [Carnap] |
| Full Idea: If someone accepts a framework for a kind of entities, then he must admit the entities as possible designata. Thus the question of the admissibility of entities is reduced to the question of the acceptability of the linguistic framework for the entities. | |
| From: Rudolph Carnap (Empiricism, Semantics and Ontology [1950], 4) | |
| A reaction: Despite the many differences of opinion between Quine and Carnap, this appears to be a straight endorsement by Carnap of the Quinean conception of ontological commitment. |
| 13935 | We only accept 'things' within a language with formation, testing and acceptance rules [Carnap] |
| Full Idea: To accept the thing world means nothing more than to accept a certain form of language, in other words, to accept rules for forming statements and for testing, accepting, or rejecting them. | |
| From: Rudolph Carnap (Empiricism, Semantics and Ontology [1950], 2) | |
| A reaction: If you derive your metaphysics from your language, then objects are linguistic conventions. But why do we accept conventions about objects? |
| 16678 | Without magnitude a thing would retain its parts, but they would have no location [Buridan] |
| Full Idea: If magnitude were removed from matter by divine power, it would still have parts distinct from one another, but they would not be positioned either outside one another or inside one another, because position would be removed. | |
| From: Jean Buridan (Questions on Aristotle's Physics [1346], I.8 f. 11va), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 14.4 | |
| A reaction: This shows why Quantity is such an important category for scholastic philosopher. |
| 16793 | A thing is (less properly) the same over time if each part is succeeded by another [Buridan] |
| Full Idea: Less properly, one thing is said to be numerically the same as another according to the continuity of distinct parts, one in succession after another. In this way the Seine is said to be the same river after a thousand years. | |
| From: Jean Buridan (Questions on Aristotle's Physics [1346], I.10, f. 13vb), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 29.3 | |
| A reaction: This is a rather good solution to the difficulty of the looser non-transitive notion of a thing being 'the same'. The Ship of Theseus endures (in the simple case) as long as you remember to replace each departing plank. Must some parts be originals? |
| 14305 | In the truth-functional account a burnt-up match was soluble because it never entered water [Carnap] |
| Full Idea: If a wooden match was completely burned up yesterday, and never placed in water at any time, is it not the case, therefore, that the match is soluble (in the truth-functional view). This follows just from the antecedent being false. | |
| From: Rudolph Carnap (Testability and Meaning [1937], I.440), quoted by Stephen Mumford - Dispositions | |
| A reaction: This, along with Edgington's nice example of the conditional command (Idea ) seems conclusive against the truth-functional account. The only defence possible is some sort of pragmatic account about implicature. |
| 16726 | Why can't we deduce secondary qualities from primary ones, if they cause them? [Buridan] |
| Full Idea: The entire difficulty in this question is why through a knowledge of the primary tangible qualities we cannot come to a knowledge of flavors or odors, since these are their causes, since we often go from knowledge of causes to knowing their effects. | |
| From: Jean Buridan (Questions on Aristotle's Posterior Analytics [1344], I.28c), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 22.2 | |
| A reaction: He is commenting on Idea 16725. Still a nice puzzle in the philosophy of mind. Will neuroscientists ever be able to infer to actual character of some quale, just from the structures of the neurons? |
| 13932 | Empiricists tend to reject abstract entities, and to feel sympathy with nominalism [Carnap] |
| Full Idea: Empiricists are in general rather suspicious with respect to any kind of abstract entities like properties, classes, relations, numbers, propositions etc. They usually feel more sympathy with nominalists than with realists (in the medieval sense). | |
| From: Rudolph Carnap (Empiricism, Semantics and Ontology [1950], 1) | |
| A reaction: The obvious reason is that you can't have sense experiences of abstract entities. I like the question 'what are they made of?' rather than the question 'how can I experience them?'. |
| 13937 | New linguistic claims about entities are not true or false, but just expedient, fruitful or successful [Carnap] |
| Full Idea: The acceptance of new linguistic forms about entities cannot be judged as being either true or false because it is not an assertion. It can only be judged as being more or less expedient, fruitful, conducive to the aim for which the language is intended. | |
| From: Rudolph Carnap (Empiricism, Semantics and Ontology [1950], 3) | |
| A reaction: The obvious problem seems to be that a complete pack of lies might be successful for a very long time, if it plugged a critical hole in a major theory. Is success judged financially? How do we judge success without mentioning truth? |
| 16577 | Induction is not demonstration, because not all of the instances can be observed [Buridan] |
| Full Idea: Inductions are not demonstrations, because they do not conclude on account of their form, since it is not possible to make an induction from all cases. | |
| From: Jean Buridan (Questions on Aristotle's Physics [1346], I.15 f. 18vb), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 02.3 | |
| A reaction: Thus showing that demonstration really is meant to be as conclusive as a mathematical proof, and that Aristotle seems to think such a thing is possible in physical science. |
| 18699 | Carnap tried to define all scientific predicates in terms of primitive relations, using type theory [Carnap, by Button] |
| Full Idea: Carnap's ultimate ambition in the Aufbau is to provide a constitution-system within which any predicate of any scientific vocabulary can be explicitly defined in terms of primitive relations holding among basic elements, using type theory. | |
| From: report of Rudolph Carnap (The Logical Structure of the World (Aufbau) [1928]) by Tim Button - The Limits of Reason 05.2 | |
| A reaction: David Chalmers has a modern shot at the same project in 'Constructing the World'. Ramsey sentences seem to be part of the same game. |
| 17601 | Neither a priori rationalism nor sense data empiricism account for scientific knowledge [Thagard] |
| Full Idea: Both rationalists (who start with a priori truths and make deductions) and empiricists (starting with indubitable sense data and what follows) would guarantee truth, but neither even begins to account for scientific knowledge. | |
| From: Paul Thagard (Coherence: The Price is Right [2012], p.46) | |
| A reaction: Thagard's answer, and mine, is inference to the best explanation, but goes beyond both the a priori truths and the perceptions. |
| 13940 | All linguistic forms in science are merely judged by their efficiency as instruments [Carnap] |
| Full Idea: The acceptance or rejection of abstract (or any other) linguistic forms in any branch of science will finally be decided by their efficiency as instruments. | |
| From: Rudolph Carnap (Empiricism, Semantics and Ontology [1950], 5) |
| 16576 | Science is based on induction, for general truths about fire, rhubarb and magnets [Buridan] |
| Full Idea: Induction should be regarded as a principle of natural science. For otherwise you could not prove that every fire is hot, that all rhubarb is purgative of bile, that every magnet attracts iron. | |
| From: Jean Buridan (Questions on Aristotle's Physics [1346], I.15 f. 18vb), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 02.3 | |
| A reaction: He is basing this on Aristotle, and refers to 'Physics' 190a33-b11. |
| 17600 | Bayesian inference is forced to rely on approximations [Thagard] |
| Full Idea: It is well known that the general problem with Bayesian inference is that it is computationally intractable, so the algorithms used for computing posterior probabilities have to be approximations. | |
| From: Paul Thagard (Coherence: The Price is Right [2012], p.45) | |
| A reaction: Thagard makes this sound devastating, but then concedes that all theories have to rely on approximations, so I haven't quite grasped this idea. He gives references. |
| 13048 | Good explications are exact, fruitful, simple and similar to the explicandum [Carnap, by Salmon] |
| Full Idea: Carnap's four criteria for giving a good explication are similarity to the explicandum, exactness, fruitfulness and simplicity. | |
| From: report of Rudolph Carnap (Logical Foundations of Probability [1950], Ch.1) by Wesley Salmon - Four Decades of Scientific Explanation 0.1 | |
| A reaction: [compressed] Salmon's view is that this represents the old attitude, that the contribution of philosophy to explanation is the clarification of the key concepts. Carnap is, of course, a logical empiricist. |
| 17064 | 1: Coherence is a symmetrical relation between two propositions [Thagard, by Smart] |
| Full Idea: 1: Coherence and incoherence are symmetrical between pairs of propositions. | |
| From: report of Paul Thagard (Explanatory Coherence [1989], 1) by J.J.C. Smart - Explanation - Opening Address p.04 |
| 17065 | 2: An explanation must wholly cohere internally, and with the new fact [Thagard, by Smart] |
| Full Idea: 2: If a set of propositions explains a further proposition, then each proposition in the set coheres with that proposition, and propositions in the set cohere pairwise with one another. | |
| From: report of Paul Thagard (Explanatory Coherence [1989], 2) by J.J.C. Smart - Explanation - Opening Address p.04 |
| 17066 | 3: If an analogous pair explain another analogous pair, then they all cohere [Thagard, by Smart] |
| Full Idea: 3: If two analogous propositions separately explain different ones of a further pair of analogous propositions, then the first pair cohere with one another, and so do the second (explananda) pair. | |
| From: report of Paul Thagard (Explanatory Coherence [1989], 3) by J.J.C. Smart - Explanation - Opening Address p.04 |
| 17067 | 4: For coherence, observation reports have a degree of intrinsic acceptability [Thagard, by Smart] |
| Full Idea: 4: Observation reports (for coherence) have a degree of acceptability on their own. | |
| From: report of Paul Thagard (Explanatory Coherence [1989], 4) by J.J.C. Smart - Explanation - Opening Address p.04 | |
| A reaction: Thagard makes this an axiom, but Smart rejects that and says there is no reason why observation reports should not also be accepted because of their coherence (with our views about our senses etc.). I agree with Smart. |
| 17068 | 5: Contradictory propositions incohere [Thagard, by Smart] |
| Full Idea: 5: Contradictory propositions incohere. | |
| From: report of Paul Thagard (Explanatory Coherence [1989], 5) by J.J.C. Smart - Explanation - Opening Address p.04 | |
| A reaction: This has to be a minimal axiom for coherence, but coherence is always taken to be more than mere logical consistency. Mutual relevance is the first step. At least there must be no category mistakes. |
| 17069 | 6: A proposition's acceptability depends on its coherence with a system [Thagard, by Smart] |
| Full Idea: 6: Acceptability of a proposition in a system depends on its coherence with the propositions in that system. | |
| From: report of Paul Thagard (Explanatory Coherence [1989], 6) by J.J.C. Smart - Explanation - Opening Address p.04 | |
| A reaction: Thagard tried to build an AI system for coherent explanations, but I would say he has no chance with these six axioms, because they never grasp the nettle of what 'coherence' means. You first need rules for how things relate. What things are comparable? |
| 17599 | The best theory has the highest subjective (Bayesian) probability? [Thagard] |
| Full Idea: On the Bayesian view, the best theory is the one with the highest subjective probability, given the evidence as calculated by Bayes's theorem. | |
| From: Paul Thagard (Coherence: The Price is Right [2012], p.45) |
| 12131 | All concepts can be derived from a few basics, making possible one science of everything [Carnap, by Brody] |
| Full Idea: In the 'Aufbau', Carnap tried to show how all of our concepts can be derived from a few basic concepts. ..Consequently there can be one science which studied all that existed, the science of the objects corresponding to the basic concepts. | |
| From: report of Rudolph Carnap (The Logical Structure of the World (Aufbau) [1928]) by Baruch Brody - Identity and Essence 2.2 | |
| A reaction: This is Carnap's Constructionist programme. |
| 11968 | The intension of a sentence is the set of all possible worlds in which it is true [Carnap, by Kaplan] |
| Full Idea: Carnap's proposal is to understand the category of intensions appropriate to sentences (his 'propositions') as sets of possible worlds. The intension of the sentence is taken as the set of all possible worlds in which the sentence is true. | |
| From: report of Rudolph Carnap (Meaning and Necessity [1947]) by David Kaplan - Transworld Heir Lines p.90 | |
| A reaction: [reference?] This extension of the truth-conditions view of meaning strikes me as being very attractive. Except that whole worlds hardly seem to be relevant to my remark about how lunch might have been improved. |
| 18285 | All translation loses some content (but language does not create reality) [Carnap] |
| Full Idea: I do not believe in translatability without loss of content, and therefore I think that the content of a world description is influenced to a certain degree by choice of a language form. But that does not mean that reality is created through language. | |
| From: Rudolph Carnap (Letters to Schlick [1935], 1935.12.04), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 19 'Truth' | |
| A reaction: It is a mistake to think Quine was the first to spot the interest of translation in philosophy of language. 'Does translation always lose content?' is a very nice question for focusing the problem. |