| 14906 | Non-positivist verificationism says only take a hypothesis seriously if it is scientifically based and testable [Ladyman/Ross on Peirce] |
| Full Idea: With Peirce, we endorse a non-positivist version of verificationism - no hypothesis should be taken seriously if apparently beyond our capacity to investigate, and serious metaphysics must concern at least two plausible scientific hypotheses. | |
| From: comment on Charles Sanders Peirce (How to Make our Ideas Clear [1878]) by J Ladyman / D Ross - Every Thing Must Go 1.3 | |
| A reaction: [compressed] They say this is NOT a theory about meaning, as 'The Big Bang was caused by Elvis' is perfectly meaningful. Verificationism always seems to rule out bold speculation. Don't say 'take string theory seriously', if we can't test it? |
| 6427 | Unverifiable propositions about the remote past are still either true or false [Russell] |
| Full Idea: There is no conceivable method by which we can discover whether the proposition 'It snowed on Manhattan Island on the 1st January in the year 1 A.D.' is true or false, but it seems preposterous to maintain that it is neither. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.10) | |
| A reaction: I love this example, which seems so simple and so clear-cut. It criticises verificationism, and gives strong intuitive support for realism, and supports the law of excluded middle. |
| 13468 | Russell started philosophy of language, by declaring some plausible sentences to be meaningless [Russell, by Hart,WD] |
| Full Idea: Russell inadvertently started the philosophy of language by declaring that some sentences (like "Everything is identical with itself") that seem utterly in order are meaningless and express no proposition. | |
| From: report of Bertrand Russell (Problems of Philosophy [1912]) by William D. Hart - The Evolution of Logic 2 | |
| A reaction: The normal candidate for this honour would be Frege, with the sense/reference distinction, but this idea sounds right to me. Declaring that some sentences are 'meaningless' really gets people excited and interested. I like the example! |
| 5388 | Every understood proposition is composed of constituents with which we are acquainted [Russell] |
| Full Idea: Every proposition which we can understand must be composed wholly of constituents with which we are acquainted. | |
| From: Bertrand Russell (Problems of Philosophy [1912], Ch. 6) | |
| A reaction: This is somewhere between Hume and logical positivism, but it concerns understanding (not meaning) of propositions (not sentences), and its acquaintance can be of universals as well as of sense experience. I like Russell's version more than Ayer's. |
| 10117 | Intuitonists in mathematics worried about unjustified assertion, as well as contradiction [Brouwer, by George/Velleman] |
| Full Idea: The concern of mathematical intuitionists was that the use of certain forms of inference generates, not contradiction, but unjustified assertions. | |
| From: report of Luitzen E.J. Brouwer (Intuitionism and Formalism [1912]) by A.George / D.J.Velleman - Philosophies of Mathematics Ch.6 | |
| A reaction: This seems to be the real origin of the verificationist idea in the theory of meaning. It is a hugely revolutionary idea - that ideas are not only ruled out of court by contradiction, but that there are other criteria which should also be met. |
| 18728 | The meaning of a proposition is the mode of its verification [Wittgenstein] |
| Full Idea: The meaning of a proposition is the mode of its verification (and two propositions cannot have the same verification). | |
| From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C I) | |
| A reaction: Does this mean that if two sentences have the same mode of verification, then they must be expressing the same proposition? I guess so. |
| 4150 | Asking about verification is only one way of asking about the meaning of a proposition [Wittgenstein] |
| Full Idea: Asking whether and how a proposition can be verified is only a particular way of asking 'How do you mean?' The answer is a contribution to the grammar of the proposition. | |
| From: Ludwig Wittgenstein (Philosophical Investigations [1952], §353) | |
| A reaction: 'How' a proposition is verified seems utterly irrelevant. What situation in reality provides the verification must have something to do with the meaning. Cat-on-mat is what counts, not whether you see it, hear it or smell it. |
| 18282 | You can't believe it if you can't imagine a verification for it [Wittgenstein] |
| Full Idea: It isn't possible to believe something for which you cannot imagine some kind of verification. | |
| From: Ludwig Wittgenstein (Philosophical Remarks [1930], p.200), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 13 'Constr' | |
| A reaction: In 1930 LW was calling this his 'old principle'. As it stands here it is too vague to assert very much. |
| 7086 | Good philosophy asserts science, and demonstrates the meaninglessness of metaphysics [Wittgenstein] |
| Full Idea: The correct method in philosophy would be to say nothing except what can be said, i.e. propositions of natural science, and whenever someone wanted to say something metaphysical, to show that he had failed to give a meaning to signs in his propositions. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.53) | |
| A reaction: This seems to be the germ of logical positivism, picked up by the Vienna Circle, and passed on the Ayer and co. How, though, do you 'show' that a sign is meaningless? Very abstract ideas are too far away from experience to be analysed that way. |
| 5164 | A statement is meaningful if observation statements can be deduced from it [Ayer] |
| Full Idea: In the improved version, a statement was verifiable, and consequently meaningful, if 'some observation-statement can be deduced from it in conjunction with certain other premises, without being deducible from those other premises alone'. | |
| From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.15) | |
| A reaction: I.Berlin showed that any statement S could pass this test, because if you assert 'S' and 'If S then O', these two statements entail O, which could be some random observation. Hence a 1946 revised version had to be produced. |
| 5165 | Directly verifiable statements must entail at least one new observation statement [Ayer] |
| Full Idea: A statement is directly verifiable if it is either itself an observation-statement,or is such that in conjunction with one or more observation-statements it entails at least one observation-statement which is not deducible from these other premises alone. | |
| From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.17) | |
| A reaction: This is the 1946 revised version of the Verification Principle, which was then torpedoed by an elaborate counterexample from Alonzo Church. Ayer thereafter abandoned attempts to find a precise statement of it. |
| 5166 | The principle of verification is not an empirical hypothesis, but a definition [Ayer] |
| Full Idea: I wish the principle of verification to be regarded, not as an empirical hypothesis, but as a definition. | |
| From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.21) | |
| A reaction: This is Ayer's attempt to meet the well known objection of 'turning the tables' on his theory (by asking whether it is tautological or empirically verifiable). However, if it is just a definition, then presumably it is completely arbitrary… |
| 5181 | A sentence is factually significant to someone if they know how to verify its proposition [Ayer] |
| Full Idea: A sentence is factually significant to any given person, if, and only if, he knows how to verify the proposition which it purports to express. | |
| From: A.J. Ayer (Language,Truth and Logic [1936], Ch.1) | |
| A reaction: 'I can't verify it, but I know a bloke who can'? 'If only I could think of a way to verify x'? 'This is unverifiable, but it is the only remaining possibility'? 'X is unverifiable, but it would nice if it was true'? Etc. |
| 5184 | Factual propositions imply (in conjunction with a few other premises) possible experiences [Ayer] |
| Full Idea: The mark of a genuinely factual proposition is that some experiential propositions can be deduced from it in conjunction with certain other premises without being deducible from those premises alone. | |
| From: A.J. Ayer (Language,Truth and Logic [1936], Ch.1) | |
| A reaction: I.Berlin showed that any statement S could pass this test, because if you assert 'S' and 'If S then O', these two statements entail O, which could be some random observation. Verificationism kept meeting problems of this kind. |
| 5186 | Tautologies and empirical hypotheses form the entire class of significant propositions [Ayer] |
| Full Idea: Tautologies and empirical hypotheses form the entire class of significant propositions. | |
| From: A.J. Ayer (Language,Truth and Logic [1936], Ch.1) | |
| A reaction: This appears to be false. Possibly the problem is that Ayer takes the whole proposition to be the unit of meaning, but actually meaninfulness only requires that we build up a claim about a possible world from semantic units. Blue bees live on square suns. |
| 8181 | A justificationist theory of meaning leads to the rejection of classical logic [Dummett] |
| Full Idea: If we adopt a justificationist theory of meaning, we must reject the universal law of excluded middle, and with it classical logic (which rests on the two-valued semantics of bivalence). We admit only intuitionist logic, which preserves justifiability. | |
| From: Michael Dummett (Thought and Reality [1997], 5) | |
| A reaction: This is Dummett's philosophy in a very neat nutshell. He seems to have started by accepting Brouwer's intuitionism, and then working back to language. It all implies anti-realism. I don't buy it. |
| 8182 | Verificationism could be realist, if we imagined the verification by a superhuman power [Dummett] |
| Full Idea: There is a possible route to realism, which has been called 'ideal verificationism', if we base our grasping the understanding and truth of a range of sentences on the procedure that would be available to an imagined being with superhuman powers. | |
| From: Michael Dummett (Thought and Reality [1997], 5) | |
| A reaction: This is actually a slippery slope for verificationists, as soon as they allow that verification could be done by other people. A verifier might turn up who had telepathy, or x-ray vision, or could see quarks... |
| 8183 | If truths about the past depend on memories and current evidence, the past will change [Dummett] |
| Full Idea: If justificationists succumb to the temptation for statements in the past, we shall view their senses as given by present memories and present traces of past events; but this will force us into a view of the past as itself changing. | |
| From: Michael Dummett (Thought and Reality [1997], 6) | |
| A reaction: Obviously Dummett attempts to sidestep this problem, but it strikes me as powerful support for the realist view about the past. How can we not be committed to the view that there are facts about the past quite unconnected to our verifying abilities? |
| 8193 | Verification is not an individual but a collective activity [Dummett] |
| Full Idea: Verification is not an individual but a collective activity. | |
| From: Michael Dummett (Truth and the Past [2001], 3) | |
| A reaction: This generates problems. Are deceased members of the community included? (Yes, says Dummett). If someone speaks to angels (Blake!), do they get included? Is a majority necessary? What of weird loners? Etc. |
| 4564 | I can meaningfully speculate that humans may have experiences currently impossible for us [Cooper,DE] |
| Full Idea: It is not meaningless for me to postulate the potential for humans to sense in a manner which is at present unimaginable and indescribable. There is no reason to believe me, but I might be right. | |
| From: David E. Cooper (Philosophy and the Nature of Language [1973], §3.1) | |
| A reaction: The key counterexample to verificationist theories of meaning is wild speculations, which are clearly meaningful, though frequently far beyond any likely human experience. Logical positivists are allergic to imagination. |
| 4565 | The verification principle itself seems neither analytic nor verifiable [Cooper,DE] |
| Full Idea: It seems that the positivists must admit that there is at least one statement which is meaningful, but which is neither verifiable nor analytic - namely, the statement of the principle of verification itself. | |
| From: David E. Cooper (Philosophy and the Nature of Language [1973], §3.1) | |
| A reaction: Some people think this objection is decisive, but I think any theory must be permitted a few metatheoretic assertions or axioms which are beyond discussion. Ayer thought the VP might be treated as analytic. Everyone has to start somewhere. |
| 2744 | Verificationism (the 'verification principle') is an earlier form of anti-realism [Dancy,J] |
| Full Idea: Verificationism (the 'verification principle') is an earlier form of anti-realism. | |
| From: Jonathan Dancy (Intro to Contemporary Epistemology [1985], 1.note) | |
| A reaction: If the one true God announced that there is a real world out there, I might take that as a verification of the fact. |
| 2760 | Logical positivism implies foundationalism, by dividing weak from strong verifications [Dancy,J] |
| Full Idea: The foundationalist claim that there are inferential and non-inferential justifications is mirrored by the claim of logical empiricism (the verification principle) that all significant statements are either strongly or weakly verifiable. | |
| From: Jonathan Dancy (Intro to Contemporary Epistemology [1985], 6.2) | |
| A reaction: I take it to be characteristic of both to divide the support for something into two types, one of which is basic, and the other built up on the basics. The first step is to decide what is basic. |
| 13410 | Verificationism about concepts means you can't deny a theory, because you can't have the concept [Papineau] |
| Full Idea: Verificationism about concepts implies that thinkers will not share concepts with adherents of theories they reject. Those who reject the phlogiston theory will not possess the same concept as adherents, so cannot say 'there is no phlogiston'. | |
| From: David Papineau (Philosophical Insignificance of A Priori Knowledge [2010], §6) | |
| A reaction: The point seems to be more general - that it is hard to see how you can have a concept of anything which doesn't actually exist, if the concept is meant to rest on some sort of empirical verification. |
| 3007 | Many different verification procedures can reach 'star', but it only has one semantic value [Fodor] |
| Full Idea: Verification procedures connect terms with their denotations in too many ways. Different routes to 'star' do not determine different semantic values for 'star'. | |
| From: Jerry A. Fodor (Psychosemantics [1987], p.125) | |
| A reaction: This fairly conclusively shows that meaning is not 'the method of verification' - but that wasn't a difficult target to hit. |
| 7883 | Verificationists tend to infer indefinite answers from undecidable questions [Papineau] |
| Full Idea: The verificationist sin is to infer an indefiniteness of answers immediately from the undecidability of questions. | |
| From: David Papineau (Thinking about Consciousness [2002], 7.02) | |
| A reaction: This remark is aimed at Dummett's anti-realism. It strikes me that what is being described really is a sort of arrogance, in believing that reality can somehow be inferred from studying the epistemic apparatus of a few miserable little mammals. |
| 13882 | A milder claim is that understanding requires some evidence of that understanding [Wright,C] |
| Full Idea: A mild version of the verification principle would say that it makes sense to think of someone as understanding an expression only if he is able, by his use of the expression, to give the best possible evidence that he understands it. | |
| From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.vii) | |
| A reaction: That doesn't seem to tell us what understanding actually consists of, and may just be the truism that to demonstrate anything whatsoever will necessarily involve some evidence. |
| 4999 | For behaviourists language is just a special kind of behaviour [Kirk,R] |
| Full Idea: Behaviourists regard the use of language as just a special kind of behaviour. | |
| From: Robert Kirk (Mind and Body [2003], §7.9) | |
| A reaction: This is not an intuitively obvious view of language. We behave, and then we talk about behaviour. Performative utterances (like promising) have an obvious behavioural aspect, as do violent threats, but not highly theoretical language (such as maths). |
| 2971 | Perhaps logical positivism showed that there is no dividing line between science and metaphysics [Lockwood] |
| Full Idea: If the logical positivists established anything it is that there is no way of demarcating science from metaphysics. | |
| From: Michael Lockwood (Mind, Brain and the Quantum [1989], p.313) | |
| A reaction: So many problems arise for philosophers because of the passion for 'demarcating' things. Close study, experiments, statistics and measurements occur in every walk of life. |
| 3181 | A one hour gap in time might be indirectly verified, but then almost anything could be [Rey] |
| Full Idea: You couldn't directly verify that the whole universe had stopped for one hour, but you might indirectly verify it (by prediction) - but then almost anything could be very indirectly verified. | |
| From: Georges Rey (Contemporary Philosophy of Mind [1997], 5.4) | |
| A reaction: Does indirect verification include time travel? Or perfect knowledge of quantum theory, and total knowledge of quantum states. Laplace's Hypothesis. |
| 10060 | Logical positivists adopted an If-thenist version of logicism about numbers [Musgrave] |
| Full Idea: Logical positivists did not adopt old-style logicism, but rather logicism spiced with varying doses of If-thenism. | |
| From: Alan Musgrave (Logicism Revisited [1977], §4) | |
| A reaction: This refers to their account of mathematics as a set of purely logical truths, rather than being either empirical, or a priori synthetic. |
| 7766 | Meaning must be known before we can consider verification [Lycan] |
| Full Idea: How could we know whether a sentence is verifiable unless we already knew what it says? | |
| From: William Lycan (Philosophy of Language [2000], Ch. 8) | |
| A reaction: This strikes me as a devastating objection to verificationism. Lycan suggests that you can formulate a preliminary meaning, without accepting true meaningfulness. Maybe verification just concerns truth, and not meaning. |
| 4710 | Verificationism was attacked by the deniers of the analytic-synthetic distinction, needed for 'facts' [O'Grady] |
| Full Idea: Verificationism came under attack from empiricists who were friendly to the banishment of traditional metaphysics, but unfriendly to the analytic-synthetic distinction, on which the idea of a 'factual statement' depended. | |
| From: Paul O'Grady (Relativism [2002], Ch.3) | |
| A reaction: I don't accept this move because I don't consider the 'facts' to be language-dependent. They are pre-linguistic, they outrun that capacity of our language, and they are available to animals. |
| 9134 | The negation of a meaningful sentence must itself be meaningful [Sorensen] |
| Full Idea: The negation of any meaningful sentence must itself be meaningful. | |
| From: Roy Sorensen (Vagueness and Contradiction [2001], 8.1) | |
| A reaction: Nice. Compare 'there is another prime number beyond the highest one we have found' with its negation. The first seems verifiable in principle, but the second one doesn't. So the verificationist must deny Sorensen's idea? |
| 5748 | We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia] |
| Full Idea: Many philosophers now concede that it is rational to accept a proposition not because we can directly verify it but because it is supported by considerations of simplicity, theoretical utility, explanatory power and/or intuitive plausibility. | |
| From: Joseph Melia (Modality [2003], Ch.5) | |
| A reaction: This suggests how the weakness of logical positivism may have led us to the concept of epistemic virtues (such as those listed), which are, of course, largely a matter of community consensus, just as the moral virtues are. |
| 17731 | Verificationism is better if it says meaningfulness needs concepts grounded in the senses [Jenkins] |
| Full Idea: I find an updated verificationism plausible, in which we say something meaningful just in case we employ only concepts whose possession could be justified or disjustified by sensory input. | |
| From: Carrie Jenkins (Grounding Concepts [2008], 5.6) | |
| A reaction: Wow! This is the first time I have ever had the slightest sympathy for verificationism. It saves my favourite problem case - of wild but meaningful speculation, for example about the contents of another universe. A very nice idea. |