47 ideas
| 8166 | Truth is part of semantics, since valid inference preserves truth [Dummett] |
| Full Idea: The concept of truth belongs to semantics, since after all truth is what must be preserved by a valid deductive inference. | |
| From: Michael Dummett (Thought and Reality [1997], 2) | |
| A reaction: Does this conclusion follow? Compare 'nice taste belongs to cooking, since that is what cooking must preserve'. I don't like this. I take 'truth' to be a relevant concept to a discussion of a dog's belief that it is going to be taken for a walk. |
| 8173 | Language can violate bivalence because of non-referring terms or ill-defined predicates [Dummett] |
| Full Idea: Two features of natural languages cause them to violate bivalence: singular terms (or proper names) which have a sense but fail to denote an object ('the centre of the universe'); and predicates which are not well defined for every object. | |
| From: Michael Dummett (Thought and Reality [1997], 4) | |
| A reaction: If we switch from sentences to propositions these problems might be avoided. If there is no reference, or a vague predicate, then there is (maybe) just no proposition being expressed which could be evaluated for truth. |
| 8179 | The law of excluded middle is the logical reflection of the principle of bivalence [Dummett] |
| Full Idea: The law of excluded middle is the reflection, within logic, of the principle of bivalence. It states that 'For any statement A, the statement 'A or not-A' is true'. | |
| From: Michael Dummett (Thought and Reality [1997], 5) | |
| A reaction: True-or-not-true is an easier condition to fulfil than true-or-false. The second says that 'false' is the only alternative, but the first allows other alternatives to 'true' (such as 'undecidable'). It is hard to challenge excluded middle. Somewhat true? |
| 458 | Nothing could come out of nothing, and existence could never completely cease [Empedocles] |
| Full Idea: From what in no wise exists, it is impossible for anything to come into being; for Being to perish completely is incapable of fulfilment and unthinkable. | |
| From: Empedocles (fragments/reports [c.453 BCE], B012), quoted by Anon (Lyc) - On Melissus 975b1-4 |
| 5112 | Empedocles says things are at rest, unless love unites them, or hatred splits them [Empedocles, by Aristotle] |
| Full Idea: Empedocles claims that things are alternately changing and at rest - that they are changing whenever love is creating a unity out of plurality, or hatred is creating plurality out of unity, and they are at rest in the times in between. | |
| From: report of Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Physics 250b26 | |
| A reaction: I suppose one must say that this an example of Ruskin's 'pathetic fallacy' - reading human emotions into the cosmos. Being constructive little creatures, we think goodness leads to construction. I'm afraid Empedocles is just wrong. |
| 8184 | Philosophers should not presume reality, but only invoke it when language requires it [Dummett] |
| Full Idea: The philosopher's task is not to make a prior commitment for or against realism, but to discover how far realist considerations must be invoked in order to describe our understanding of our language: they may be invoked only if they must be invoked. | |
| From: Michael Dummett (Thought and Reality [1997], 6) | |
| A reaction: I don't see why the default position should be solipsism, or a commitment to Ockham's Razor. This is the Cartesian 'Enlightenment Project' approach to philosophy - that everything has to be proved. There is more to ontology than language. |
| 8185 | We can't make sense of a world not apprehended by a mind [Dummett] |
| Full Idea: We can make no clear sense of there being a world that is not apprehended by any mind. | |
| From: Michael Dummett (Thought and Reality [1997], 8) | |
| A reaction: I find Dummett's view quite baffling. It is no coincidence that Dummett is a theist, along (it seems) Berkeleian lines. I see no more problem with imagining such worlds than with imagining ships sunken long ago which will never be found. |
| 8163 | Since 'no bird here' and 'no squirrel here' seem the same, we must talk of 'atomic' facts [Dummett] |
| Full Idea: What complex of objects constitutes the fact that there is no bird on the bough, and how is that distinct from no squirrel on the bough? This drives us to see the world as composed of 'atomic' facts, making complexes into compounds, not reality itself. | |
| From: Michael Dummett (Thought and Reality [1997], 1) | |
| A reaction: [He cites early Wittgenstein as an example] But 'no patch of red here' (or sense-datum) seems identical to 'no patch of green here'. I suppose you could catalogue all the atomic facts, and note that red wasn't among them. But you could do that for birds. |
| 8161 | We know we can state facts, with true statements [Dummett] |
| Full Idea: One thing we know about facts, namely that we can state them. Whenever we make some true statement, we state some fact. | |
| From: Michael Dummett (Thought and Reality [1997], 1) | |
| A reaction: Then facts become boring, and are subsumed within the problem of what 'true' means. Personally I have a concept of facts which includes unstatable facts. The physical basis of melancholy I take to be a complex fact which is beyond our powers. |
| 8180 | 'That is red or orange' might be considered true, even though 'that is red' and 'that is orange' were not [Dummett] |
| Full Idea: A statement of the form 'that is red or orange', said of something on the borderline between the two colours, might rank as true, although neither 'that is red' nor 'that is orange' was true. | |
| From: Michael Dummett (Thought and Reality [1997], 5) | |
| A reaction: It seems to me that the problem here would be epistemological rather than ontological. One of the two is clearly true, but sometimes we can't decide which. How can anyone say 'It isn't red and it isn't orange, but it is either red or orange'? |
| 13209 | There is no coming-to-be of anything, but only mixing and separating [Empedocles, by Aristotle] |
| Full Idea: Empedocles says there is no coming-to-be of anything, but only a mingling and a divorce of what has been mingled. | |
| From: report of Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 314b08 | |
| A reaction: Aristotle comments that this prevents Empedocleans from distinguishing between superficial alteration and fundamental change of identity. Presumably, though, that wouldn't bother them. |
| 457 | Substance is not created or destroyed in mortals, but there is only mixing and exchange [Empedocles] |
| Full Idea: There is no creation of substance in any one of mortal existence, nor any end in execrable death, but only mixing and exchange of what has been mixed. | |
| From: Empedocles (fragments/reports [c.453 BCE], B008), quoted by Plutarch - 74: Reply to Colotes 1111f | |
| A reaction: also Aristotle 314b08 |
| 8808 | Involuntary beliefs can still be evaluated [Feldman/Conee] |
| Full Idea: Examples confirm that beliefs may be both involuntary and subject to epistemic evaluation. | |
| From: R Feldman / E Conee (Evidentialism [1985], II) | |
| A reaction: This is an extremely important point, which summarises the situation with beliefs that arise from (apparent) immediate perception. A belief cannot possibly be knowledge if it has been triggered, but no effort was made to evaluate it. |
| 8178 | Empirical and a priori knowledge are not distinct, but are extremes of a sliding scale [Dummett] |
| Full Idea: Our sentences cannot be divided into two classes, empirical and a priori, the truth of one to be decided by observation, the other by ratiocination. They lie on a scale, with observational sentences at one end, and mathematical ones at the other. | |
| From: Michael Dummett (Thought and Reality [1997], 5) | |
| A reaction: The modern post-Kantian dissolution of the rationalist-empiricist debate. I would say that mathematical sentences require no empirical evidence (for their operation, rather than foundation), but a bit of reasoning is involved in observation. |
| 8807 | Evidentialism is the view that justification is determined by the quality of the evidence [Feldman/Conee] |
| Full Idea: What we call 'evidentialism' is the view that the epistemic justification of a belief is determined by the quality of the believer's evidence for the belief. | |
| From: R Feldman / E Conee (Evidentialism [1985], I) | |
| A reaction: The immediate question is whether the believer knows the quality of their evidence. A detective might not recognise the crucial clue (like the dog not barking). The definition of 'quality' had better not turn out to be circular. Forgotten evidence? |
| 8809 | Beliefs should fit evidence, and if you ought to believe it, then you are justified [Feldman/Conee] |
| Full Idea: One epistemically ought to have the doxastic attitudes that fit one's evidence. Being epistemically obligatory is equivalent to being epistemically justified. | |
| From: R Feldman / E Conee (Evidentialism [1985], III) | |
| A reaction: It is normal for someone to refuse to accept something, when another person believes the evidence is overwhelming. Evaluation of evidence must include an assessment of what other evidence might turn up. |
| 8810 | If someone rejects good criticism through arrogance, that is irrelevant to whether they have knowledge [Feldman/Conee] |
| Full Idea: If an arrogant young physicist refuses to recognise valid criticisms from a senior colleague, his or her character has nothing to do with the epistemic status of their belief in the theory. | |
| From: R Feldman / E Conee (Evidentialism [1985], III) | |
| A reaction: This rejects the idea that epistemic justification is essentially a matter of virtues and vices of character. That view is a version of reliabilism, and hence of externalism. I agree with the criticism, but epistemic virtues are still significant. |
| 462 | One vision is produced by both eyes [Empedocles] |
| Full Idea: One vision is produced by both eyes | |
| From: Empedocles (fragments/reports [c.453 BCE], B088), quoted by Strabo - works 8.364.3 |
| 22765 | Wisdom and thought are shared by all things [Empedocles] |
| Full Idea: Wisdom and power of thought, know thou, are shared in by all things. | |
| From: Empedocles (fragments/reports [c.453 BCE]), quoted by Sextus Empiricus - Against the Logicians (two books) II.286 | |
| A reaction: Sextus quotes this, saying that it is 'still more paradoxical', and that it explicitly includes plants. This may mean that Empedocles was not including inanimate matter. |
| 1524 | For Empedocles thinking is almost identical to perception [Empedocles, by Theophrastus] |
| Full Idea: Empedocles assumes that thinking is either identical to or very similar to sense-perception. | |
| From: report of Empedocles (fragments/reports [c.453 BCE], A86) by Theophrastus - On the Senses 9 | |
| A reaction: Not to be sniffed at. We can, of course, control our thinking (though we can't control the controller) and we contemplate abstractions, but that might be seen as a sort of perception. Vision is not as visual as we think. |
| 8175 | A theory of thought will include propositional attitudes as well as propositions [Dummett] |
| Full Idea: A comprehensive theory of thought will include such things as judgement and belief, as well as the mere grasp of propositions. | |
| From: Michael Dummett (Thought and Reality [1997], 4) | |
| A reaction: This seems to make any theory of thought a neat two-stage operation. Beware of neatness. While propositions might be explained using concepts, syntax and truth, the second stage looks faintly daunting. See Idea 2209, for example. |
| 8174 | The theories of meaning and understanding are the only routes to an account of thought [Dummett] |
| Full Idea: For the linguistic philosopher, the theory of meaning, and the theory of understanding that is built upon it, form the only route to a philosophical account of thought. | |
| From: Michael Dummett (Thought and Reality [1997], 4) | |
| A reaction: I am of the party that thinks thought is prior to language (esp. because of animals), but Dummett's idea does not deny this. He may well be right that this is the 'only route'. We can only hope to give an account of human thought. |
| 8165 | To 'abstract from' is a logical process, as opposed to the old mental view [Dummett] |
| Full Idea: The phrase 'abstracted from' does not refer to the mental process of abstraction by disregarding features of concrete objects, in which many nineteenth century thinkers believed; it is a logical (not mental) process of concept-formation. | |
| From: Michael Dummett (Thought and Reality [1997], 1) | |
| A reaction: I take Frege's attack on 'psychologism' to be what dismissed the old view (Idea 5816). Could one not achieve the same story by negating properties in quantified logical expressions, instead of in the mind? |
| 8168 | To know the truth-conditions of a sentence, you must already know the meaning [Dummett] |
| Full Idea: You can know the condition for a sentence to be true only when you know what the sentence means. | |
| From: Michael Dummett (Thought and Reality [1997], 3) | |
| A reaction: This makes the truth-conditions theory of meaning circular, and is Dummett's big objection to Davidson's view. The composition of a sentence creates a model of a world. Truth-conditions may only presuppose knowledge of concepts. |
| 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? |
| 8176 | We could only guess the meanings of 'true' and 'false' when sentences were used [Dummett] |
| Full Idea: Even if we guessed that the two words denoted the two truth-values, we should not know which stood for the value 'true' and which for the value 'false' until we knew how the sentences were in practice used. | |
| From: Michael Dummett (Thought and Reality [1997], 4) | |
| A reaction: These types of problem are always based on the idea that some one item must have logical priority in the process, but there is a lot of room for benign circularity in the development of mental and linguistic functions. |
| 8170 | Sentences are the primary semantic units, because they can say something [Dummett] |
| Full Idea: While words are semantic atoms, sentences remain the primary semantic units, in the sense of the smallest bits of language by means of which it is possible to say anything. | |
| From: Michael Dummett (Thought and Reality [1997], 3) | |
| A reaction: Syncategorematic terms (look it up!) may need sentences, but most nouns and verbs can communicate quite a lot on their own. Whether words or sentences come first may not be a true/false issue. |
| 8169 | We can't distinguish a proposition from its content [Dummett] |
| Full Idea: No distinction can be drawn between a proposition and its content; no two distinct propositions can have the same content. | |
| From: Michael Dummett (Thought and Reality [1997], 3) | |
| A reaction: And one proposition cannot have two possible contents (ambiguity). Are we to say that a proposition supervenes on its content, or that proposition and content are identical? Ockham favours the latter. |
| 552 | Empedocles said good and evil were the basic principles [Empedocles, by Aristotle] |
| Full Idea: Empedocles was the first to give evil and good as principles. | |
| From: report of Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Metaphysics 985a | |
| A reaction: Once you start to think that good and evil will only matter if they have causal powers, it is an easy step to the idea of a benevolent god, and a satanic anti-god. Otherwise the 'principles' could be ignored. |
| 589 | 'Nature' is just a word invented by people [Empedocles] |
| Full Idea: Nature is but a word of human framing. | |
| From: Empedocles (fragments/reports [c.453 BCE], B008), quoted by Aristotle - Metaphysics 1015a |
| 21823 | The principle of 'Friendship' in Empedocles is the One, and is bodiless [Empedocles, by Plotinus] |
| Full Idea: In Empedocles we have a dividing principle, 'Strife', set against 'Friendship' - which is the One and is to him bodiless, while the elements represent matter. | |
| From: report of Empedocles (fragments/reports [c.453 BCE]) by Plotinus - The Enneads 5.1.09 | |
| A reaction: The first time I've seen the principle of Love in Empedocles identified with the One of Parmenides. Plotinus is a trustworthy reporter, I think, because he was well read, and had access to lost texts. |
| 2680 | Empedocles said that there are four material elements, and two further creative elements [Empedocles, by Aristotle] |
| Full Idea: Empedocles holds that the corporeal elements are four, but that all the elements, including those which create motion, are six in number. | |
| From: report of Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 314a16 |
| 6002 | Empedocles says bone is water, fire and earth in ratio 2:4:2 [Empedocles, by Inwood] |
| Full Idea: Empedocles used numerical ratios to explain different kinds of matter; for example, bone is two parts water, four parts fire, two parts earth; and blood is an equal blend of all four elements. | |
| From: report of Empedocles (fragments/reports [c.453 BCE]) by Brad Inwood - Empedocles | |
| A reaction: Why isn't the ration 1:2:1? This presumably shows the influence of Pythagoras (who had also been based in Italy, like Empedocles), as well as that of the earlier naturalistic philosophers. It was a very good theory, though wrong. |
| 13207 | Fire, Water, Air and Earth are elements, being simple as well as homoeomerous [Empedocles, by Aristotle] |
| Full Idea: Empedocles says that Fire, Water, Air and Earth are four elements, and are thus 'simple' rather than flesh, bone and bodies which, like these, are 'homoeomeries'. | |
| From: report of Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 314a26 | |
| A reaction: The translation is not quite clear. I take it that flesh and bone may look simple, because they are homoeomerous, but they are not really - but what is his evidence for that? Compare Idea 13208. |
| 459 | All change is unity through love or division through hate [Empedocles] |
| Full Idea: These elements never cease their continuous exchange, sometimes uniting under the influence of Love, so that all become One, at other times again moving apart through the hostile force of Hate. | |
| From: Empedocles (fragments/reports [c.453 BCE], B017), quoted by Simplicius - On Aristotle's 'Physics' 158.1- |
| 13218 | The elements combine in coming-to-be, but how do the elements themselves come-to-be? [Aristotle on Empedocles] |
| Full Idea: Empedocles says it is evident that all the other bodies down to the 'elements' have their coming-to-be and their passing-away: but it is not clear how the 'elements' themselves, severally in their aggregated masses, come-to-be and pass-away. | |
| From: comment on Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 325b20 | |
| A reaction: Presumably the elements are like axioms - and are just given. How do electrons and quarks come-to-be? |
| 13225 | Love and Strife only explain movement if their effects are distinctive [Aristotle on Empedocles] |
| Full Idea: It is not an adequate explanation to say that 'Love and Strife set things moving', unless the very nature of Love is a movement of this kind and the very nature of Strife a movement of that kind. | |
| From: comment on Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 333b23 | |
| A reaction: I take this to be of interest for showing Aristotle's quest for explanations, and his unwillingness to be fobbed off with anything superficial. I take a task of philosophy to be to push explanations further than others wish to go. |
| 460 | If the one Being ever diminishes it would no longer exist, and what could ever increase it? [Empedocles] |
| Full Idea: Besides these elements, nothing else comes into being, nor does anything cease. For if they had been perishing continuously, they would Be no more; and what could increase the Whole? And whence could it have come? | |
| From: Empedocles (fragments/reports [c.453 BCE], B017), quoted by Simplicius - On Aristotle's 'Physics' 158.1- |
| 8186 | Time is the measure of change, so we can't speak of time before all change [Dummett] |
| Full Idea: Time is the measure of change, and it makes no sense to speak of how things were before there was anything that changed. | |
| From: Michael Dummett (Thought and Reality [1997], 8) | |
| A reaction: Something creating its own measure sounds like me marking my own exam papers. If an object appears, then inverts five seconds later, how can the inversion create the five seconds? How does that differ from inverting ten seconds later? |
| 8167 | If Presentism is correct, we cannot even say that the present changes [Dummett] |
| Full Idea: If Presentism is correct - the doctrine that there is nothing at all, save what holds good at the present moment - then we cannot even say that the present changes, because that requires that things are not now as they were some time ago. | |
| From: Michael Dummett (Thought and Reality [1997], 2) | |
| A reaction: Presumably we can compare our present memory with our present experience. See Idea 6668. The logic (very ancient!) is that the present has not duration at all, and so no experiences can occur during it. |
| 5090 | Maybe bodies are designed by accident, and the creatures that don't work are destroyed [Empedocles, by Aristotle] |
| Full Idea: Is it just an accident that teeth and other parts of the body seem to have some purpose, and creatures survive because they happen to be put together in a useful way? Everything else has been destroyed, as Empedocles says of his 'cow with human head'. | |
| From: report of Empedocles (fragments/reports [c.453 BCE], 61) by Aristotle - Physics 198b29 | |
| A reaction: Good grief! Has no one ever noticed that Empedocles proposed the theory of evolution? It isn't quite natural selection, because we aren't told what does the 'destroying', but it is a little flash of genius that was quietly forgotten. |
| 461 | God is a pure, solitary, and eternal sphere [Empedocles] |
| Full Idea: God is equal in all directions to himself and altogether eternal, a rounded Sphere enjoying a circular solitude. | |
| From: Empedocles (fragments/reports [c.453 BCE], B028), quoted by John Stobaeus - Anthology 1.15.2 |
| 466 | God is pure mind permeating the universe [Empedocles] |
| Full Idea: God is mind, holy and ineffable, and only mind, which darts through the whole cosmos with its swift thought. | |
| From: Empedocles (fragments/reports [c.453 BCE], B134), quoted by Ammonius - On 'De Interpretatione' 4.5.249.6 |
| 1719 | In Empedocles' theory God is ignorant because, unlike humans, he doesn't know one of the elements (strife) [Aristotle on Empedocles] |
| Full Idea: It is a consequence of Empedocles' view that God is the most unintelligent thing, for he alone is ignorant of one of the elements, namely strife, whereas mortal creatures are familiar with them all. | |
| From: comment on Empedocles (fragments/reports [c.453 BCE]) by Aristotle - De Anima 410b08 |
| 1522 | It is wretched not to want to think clearly about the gods [Empedocles] |
| Full Idea: Wretched is he who cares not for clear thinking about the gods. | |
| From: Empedocles (fragments/reports [c.453 BCE], B132), quoted by Clement - Miscellanies 5.140.5.1 |