53 ideas
| 421 | Men who love wisdom must be inquirers into very many things indeed [Heraclitus] |
| Full Idea: Men who love wisdom must be inquirers into very many things indeed. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B035), quoted by Clement - Miscellanies 5.140.5 | |
| A reaction: …which invites the question 'Is there anything that a wisdom-seeker should NOT be interested in?' |
| 1491 | Everyone has the potential for self-knowledge and sound thinking [Heraclitus] |
| Full Idea: Everyone has the potential for self-knowledge and sound thinking. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B116), quoted by John Stobaeus - Anthology 3.05.06 | |
| A reaction: This is true. When people are labelled as incapable of philosophy (e.g. by Plato), it is just that they are slow developers. |
| 5863 | Reason is eternal, but men are foolish [Heraclitus] |
| Full Idea: Although reason exists forever, men are foolish. | |
| From: Heraclitus (fragments/reports [c.500 BCE]), quoted by Aristotle - The Art of Rhetoric 1407b | |
| A reaction: The despair of all philosophers (e.g. Plato) who think reason is the easiest thing in the world, and stares everyone in the face, and yet people seem to spurn this supreme gift from the gods. They needed the optimism of the career teacher. |
| 414 | Logos is common to all, but most people live as if they have a private understanding [Heraclitus] |
| Full Idea: Although the universal law (logos) is common to all, the majority live as if they had understanding peculiar to themselves. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B002), quoted by Sextus Empiricus - Against the Professors (six books) 7.133.4- | |
| A reaction: Heraclitus mentions 'logos' in just three fragments - this one, and Idea 15660 and Idea 424. |
| 416 | Beautiful harmony comes from things that are in opposition to one another [Heraclitus] |
| Full Idea: That which is in opposition is in concert, and from things that differ comes the beautiful harmony. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B008), quoted by Aristotle - Nicomachean Ethics 1155b04 |
| 425 | A thing can have opposing tensions but be in harmony, like a lyre [Heraclitus] |
| Full Idea: They do not understand how that which differs with itself is in agreement: harmony consists of opposing tensions, like that of the bow and the lyre. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B051), quoted by Hippolytus - Refutation of All Heresies 9.9.2 | |
| A reaction: Like squabbling couples who resent outside intervention. The remark suggests the virtues of 'dialectic', and may get to the heart of what philosophy is. |
| 7791 | The simplest of the logics based on possible worlds is Lewis's S5 [Lewis,CI, by Girle] |
| Full Idea: C.I.Lewis constructed five axiomatic systems of modal logic, and named them S1 to S5. It turns out that the simplest of the logics based on possible worlds is the same as Lewis's S5. | |
| From: report of C.I. Lewis (works [1935]) by Rod Girle - Modal Logics and Philosophy 2.1 | |
| A reaction: Nathan Salmon ('Reference and Essence' 2nd ed) claims (on p.xvii) that "the correct modal logic is weaker than S5 and weaker even than S4". Which is the greater virtue, simplicity or weakness? |
| 9358 | There are several logics, none of which will ever derive falsehoods from truth [Lewis,CI] |
| Full Idea: The fact is that there are several logics, markedly different, each self-consistent in its own terms and such that whoever, using it, avoids false premises, will never reach a false conclusion. | |
| From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.366) | |
| A reaction: As the man who invented modal logic in five different versions, he speaks with some authority. Logicians now debate which version is the best, so how could that be decided? You could avoid false conclusions by never reasoning at all. |
| 1312 | If everything is and isn't then everything is true, and a midway between true and false makes everything false [Aristotle on Heraclitus] |
| Full Idea: The remark of Heraclitus that all things are and are not effectively renders all assertions true, and that of Anaxagoras that there is an intermediary between assertion and negation makes all assertions false. | |
| From: comment on Heraclitus (fragments/reports [c.500 BCE]) by Aristotle - Metaphysics 1012a | |
| A reaction: Compare Idea 416. Heraclitus is discussing truth-value 'gluts', as in paraconsistent logic, and Anaxagoras is discussing truth-value 'gaps', as in three-valued Kleene logic. |
| 9357 | Excluded middle is just our preference for a simplified dichotomy in experience [Lewis,CI] |
| Full Idea: The law of excluded middle formulates our decision that whatever is not designated by a certain term shall be designated by its negative. It declares our purpose to make a complete dichotomy of experience, ..which is only our penchant for simplicity. | |
| From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.365) | |
| A reaction: I find this view quite appealing. 'Look, it's either F or it isn't!' is a dogmatic attitude which irritates a lot of people, and appears to be dispensible. Intuitionists in mathematics dispense with the principle, and vagueness threatens it. |
| 9364 | Names represent a uniformity in experience, or they name nothing [Lewis,CI] |
| Full Idea: A name must represent some uniformity in experience or it names nothing. | |
| From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.368) | |
| A reaction: I like this because, in the quintessentially linguistic debate about the exact logical role of names, it reminds us that names arise because of the way reality is; they are not sui generis private games for logicians. |
| 15658 | The hidden harmony is stronger than the visible [Heraclitus] |
| Full Idea: The hidden harmony is stronger (or 'better') than the visible. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B055), quoted by Hippolytus - Refutation of All Heresies 9.9.5 | |
| A reaction: 'An unapparent connection [harmonia] is stronger than an apparent one' is Curd's translation. I'm taking this for essentialism. It is the basic idea of the essentialising child (see Gelman). The hidden explains the apparent. |
| 13782 | Everything gives way, and nothing stands fast [Heraclitus] |
| Full Idea: Everything gives way, and nothing stands fast. | |
| From: Heraclitus (fragments/reports [c.500 BCE]), quoted by Plato - Cratylus 402a | |
| A reaction: This is as good a summary of the Heraclitus view of things as any, and Plato appears to present it as a verbatim quotation. |
| 11853 | A mixed drink separates if it is not stirred [Heraclitus] |
| Full Idea: The mixed drink, of wine, cheese and barley, separates if it is not stirred. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B125) | |
| A reaction: Wiggins quotes this, because it seems to be Heraclitus struggling to decide what sortal his drink falls under. I take it to be a problem of vagueness, since separation and mixing occur along a continuum, like a sorites. |
| 427 | It is not possible to step twice into the same river [Heraclitus] |
| Full Idea: It is not possible to step twice into the same river. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B091), quoted by Plutarch - 24: The E at Delphi 392b10- |
| 11091 | You can bathe in the same river twice, but not in the same river stage [Quine on Heraclitus] |
| Full Idea: You can bathe in the same river twice, but not in the same river stage. | |
| From: comment on Heraclitus (fragments/reports [c.500 BCE]) by Willard Quine - Identity, Ostension, and Hypostasis 1 | |
| A reaction: This seems to make Quine a 'perdurantist', committed to time-slices of objects, rather than whole objects enduring through change. |
| 2064 | If flux is continuous, then lack of change can't be a property, so everything changes in every possible way [Plato on Heraclitus] |
| Full Idea: According to Heracliteans, since things must be changing, and since lack of change can't be a property of anything, then everything is always undergoing change of every kind. | |
| From: comment on Heraclitus (fragments/reports [c.500 BCE], B030) by Plato - Theaetetus 182a |
| 11002 | Equating necessity with informal provability is the S4 conception of necessity [Lewis,CI, by Read] |
| Full Idea: C.I.Lewis's S4 system develops a sense of necessity as 'provability' in some fairly informal sense. | |
| From: report of C.I. Lewis (works [1935]) by Stephen Read - Thinking About Logic Ch. 4 |
| 9362 | Necessary truths are those we will maintain no matter what [Lewis,CI] |
| Full Idea: Those laws and those laws only have necessary truth which we are prepared to maintain, no matter what. | |
| From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.367) | |
| A reaction: This bold and simple claim has famously been torpedoed by a well-known counterexample - that virtually every human being will cling on to the proposition "dogs have at some time existed" no matter what, but it clearly isn't a necessary truth. |
| 7803 | Modal logic began with translation difficulties for 'If...then' [Lewis,CI, by Girle] |
| Full Idea: C.I.Lewis began his groundbreaking work in modal logic because he was concerned about the unreliability of the material conditional as a translation of 'If ... then' conditionals. | |
| From: report of C.I. Lewis (Symbolic Logic (with Langford) [1932]) by Rod Girle - Modal Logics and Philosophy 12.3 | |
| A reaction: Compare 'if this is square then it has four corners' with 'if it rains then our afternoon is ruined'. Different modalities seem to be involved. We even find that 'a square has four corners' will be materially implied if it rains! |
| 9365 | We can maintain a priori principles come what may, but we can also change them [Lewis,CI] |
| Full Idea: The a priori contains principles which can be maintained in the face of all experience, representing the initiative of the mind. But they are subject to alteration on pragmatic grounds, if expanding experience shows their intellectual infelicity. | |
| From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.373) | |
| A reaction: [compressed] This simply IS Quine's famous 'web of belief' picture, showing how firmly Quine is in the pragmatist tradition. Lewis treats a priori principles as a pragmatic toolkit, which can be refined to be more effective. Not implausible... |
| 430 | Senses are no use if the soul is corrupt [Heraclitus] |
| Full Idea: The eyes and ears are bad witnesses for men if they have barbarian souls. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B107), quoted by Sextus Empiricus - Against the Mathematicians 7.126 |
| 1500 | When we sleep, reason closes down as the senses do [Heraclitus, by Sext.Empiricus] |
| Full Idea: Since when we sleep the senses are closed, mind is separated from its surroundings and loses the power of memory. When we wake the mind re-contacts the world, and regains the power of reason. | |
| From: report of Heraclitus (fragments/reports [c.500 BCE], A16) by Sextus Empiricus - Against the Professors (six books) 7.130 |
| 21500 | We rely on memory for empirical beliefs because they mutually support one another [Lewis,CI] |
| Full Idea: When the whole range of empirical beliefs is taken into account, all of them more or less dependent on memorial knowledge, we find that those which are most credible can be assured by their mutual support, or 'congruence'. | |
| From: C.I. Lewis (An Analysis of Knowledge and Valuation [1946], 334), quoted by Erik J. Olsson - Against Coherence 3.1 | |
| A reaction: Lewis may be over-confident about this, and is duly attacked by Olson, but it seems to me roughly correct. How do you assess whether some unusual element in your memory was a dream or a real experience? |
| 21501 | If we doubt memories we cannot assess our doubt, or what is being doubted [Lewis,CI] |
| Full Idea: To doubt our sense of past experience as founded in actuality, would be to lose any criterion by which either the doubt itself or what is doubted could be corroborated. | |
| From: C.I. Lewis (An Analysis of Knowledge and Valuation [1946], 358), quoted by Erik J. Olsson - Against Coherence 3.3.1 | |
| A reaction: Obviously scepticism about memory can come in degrees, but total rejection of short-term and clear memories looks like a non-starter. What could you put in its place? Hyper-rationalism? Even maths needs memory. |
| 6556 | If anything is to be probable, then something must be certain [Lewis,CI] |
| Full Idea: If anything is to be probable, then something must be certain. | |
| From: C.I. Lewis (An Analysis of Knowledge and Valuation [1946], 186), quoted by Robert Fogelin - Walking the Tightrope of Reason Intro | |
| A reaction: Lewis makes this comment when facing infinite regress problems. It is a very nice slogan for foundationalism, which embodies the slippery slope view. Personally I feel the emotional pull of foundations, but acknowledge the very strong doubts about them. |
| 21498 | Congruents assertions increase the probability of each individual assertion in the set [Lewis,CI] |
| Full Idea: A set of statements, or a set of supposed facts asserted, will be said to be congruent if and only if they are so related that the antecedent probability of any one of them will be increased if the remainder of the set can be assumed as given premises. | |
| From: C.I. Lewis (An Analysis of Knowledge and Valuation [1946], 338), quoted by Erik J. Olsson - Against Coherence 2.2 | |
| A reaction: This thesis is vigorously attacked by Erik Olson, who works through the probability calculations. There seems an obvious problem without that. How else do you assess 'congruence', other than by evidence of mutual strengthening? |
| 417 | Donkeys prefer chaff to gold [Heraclitus] |
| Full Idea: Donkeys prefer chaff to gold. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B009), quoted by Aristotle - Nicomachean Ethics 1176a07 |
| 426 | Sea water is life-giving for fish, but not for people [Heraclitus] |
| Full Idea: Sea-water is the purest and the most polluted: for fish it is drinkable and life-giving; for men, not drinkable and destructive. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B061), quoted by Hippolytus - Refutation of All Heresies 9.10.5 |
| 431 | Health, feeding and rest are only made good by disease, hunger and weariness [Heraclitus] |
| Full Idea: Disease makes health pleasant and good, hunger makes satisfaction good, weariness makes rest good. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B111), quoted by John Stobaeus - Anthology 3.1.178 |
| 5828 | Extension is the class of things, intension is the correct definition of the thing, and intension determines extension [Lewis,CI] |
| Full Idea: "The denotation or extension of a term is the class of all actual or existent things which the term correctly applies to or names; the connotation or intension of a term is delimited by any correct definition of it." ..And intension determines extension. | |
| From: C.I. Lewis (An Analysis of Knowledge and Valuation [1946]), quoted by Stephen P. Schwartz - Intro to Naming,Necessity and Natural Kinds §II | |
| A reaction: The last part is one of the big ideas in philosophy of language, which was rejected by Putnam and co. If you were to reverse the slogan, though, (to extension determines intension) how would you identify the members of the extension? |
| 9361 | We have to separate the mathematical from physical phenomena by abstraction [Lewis,CI] |
| Full Idea: Physical processes present us with phenomena in which the purely mathematical has to be separated out by abstraction. | |
| From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.367) | |
| A reaction: This is the father of modal logic endorsing traditional abstractionism, it seems. He is also, though, endorsing the view that a priori knowledge is created by us, with pragmatic ends in view. |
| 429 | To God (though not to humans) all things are beautiful and good and just [Heraclitus] |
| Full Idea: To God, all things are beautiful, good and just; but men have assumed some things to be unjust, others just. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B102), quoted by Porphyry - Notes on Homer Il.4.4 | |
| A reaction: The idea that all things are actually 'just' strikes me as nonsense. I also don't think I can get my head round the idea that everything is actually good and beautiful. Must try harder. |
| 12294 | Good and evil are the same thing [Heraclitus, by Aristotle] |
| Full Idea: Heraclitus said that good and evil are the same thing. | |
| From: report of Heraclitus (fragments/reports [c.500 BCE], 58/102) by Aristotle - Topics 159b32 | |
| A reaction: Heaven knows what he meant by this, though it sounds suspiciously like moral nihilism. Maybe Heraclitus was not a very nice man. Or is the thought a more sophisticated one, in line with Nietzsche's remarks about cultural morality? |
| 419 | If one does not hope, one will not find the unhoped-for, since nothing leads to it [Heraclitus] |
| Full Idea: If one does not hope, one will not find the unhoped-for, since there is no trail leading to it and no path. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B018), quoted by Clement - Miscellanies 2.17.4 | |
| A reaction: The best remark about hope I have ever encountered. Usually they are empty platitudes. |
| 415 | If happiness is bodily pleasure, then oxen are happy when they have vetch to eat [Heraclitus] |
| Full Idea: If happiness lay in bodily pleasures, we would call oxen happy when they find vetch to eat. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B004), quoted by Albertus Magnus - On Vegetables 6.401 | |
| A reaction: But surely oxen are happy when they find some good vetch? Presumably, though, they are not 'eudaimon'. What is the complete fulfilment of life for an ox? |
| 5155 | It is hard to fight against emotion, but harder still to fight against pleasure [Heraclitus] |
| Full Idea: It is hard to fight against emotion, but harder still to fight against pleasure. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B085), quoted by Aristotle - Nicomachean Ethics 1105a08 | |
| A reaction: 'Emotion' is the Greek word 'thumos'. "The only way to get rid of a temptation is to yield to it", said Oscar Wilde. Heraclitus underestimates how very good many modern people are at dieting. |
| 433 | For man character is destiny [Heraclitus] |
| Full Idea: For man character is destiny. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B119), quoted by John Stobaeus - Anthology 4.40.23 | |
| A reaction: This is the extreme opposite of Sartre's existentialist claim that we can entirely change ourselves. Personally I am with Heraclitus, though I don't see why our destined character shouldn't be modified (e.g. by education). |
| 7903 | The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna] |
| Full Idea: The six perfections are of giving, morality, patience, vigour, meditation, and wisdom. | |
| From: Nagarjuna (Mahaprajnaparamitashastra [c.120], 88) | |
| A reaction: What is 'morality', if giving is not part of it? I like patience and vigour being two of the virtues, which immediately implies an Aristotelian mean (which is always what is 'appropriate'). |
| 422 | The people should fight for the law as if for their city-wall [Heraclitus] |
| Full Idea: The people should fight for the law as if for their city-wall. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B044), quoted by Diogenes Laertius - Lives of Eminent Philosophers 09.2 | |
| A reaction: This may be the first recorded assertion of the rule of law, and hence of the separation of powers. We still have plenty of people who reject this principle. |
| 614 | Heraclitus said sometimes everything becomes fire [Heraclitus, by Aristotle] |
| Full Idea: Heraclitus claimed that from time to time everything becomes fire. | |
| From: report of Heraclitus (fragments/reports [c.500 BCE]) by Aristotle - Metaphysics 1067a |
| 424 | Reason tells us that all things are one [Heraclitus] |
| Full Idea: When you have listened, not to me but to the law (logos), it is wise to agree that all things are one. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B050), quoted by Hippolytus - Refutation of All Heresies 9.9.1 |
| 5096 | Heraclitus says that at some time everything becomes fire [Heraclitus, by Aristotle] |
| Full Idea: Heraclitus says that at some time everything becomes fire. | |
| From: report of Heraclitus (fragments/reports [c.500 BCE]) by Aristotle - Physics 204b37 | |
| A reaction: Modern cosmology says that Heraclitus was right (pretty much). If we say 'energy' instead of 'fire' (which may be what he meant), then he is absolutely spot-on. |
| 17539 | The sayings of Heraclitus are still correct, if we replace 'fire' with 'energy' [Heraclitus, by Heisenberg] |
| Full Idea: If we replace Heraclitus's word 'fire' by the word 'energy' we can almost repeat his statements word for word from our modern point of view. | |
| From: report of Heraclitus (fragments/reports [c.500 BCE]) by Werner Heisenberg - Physics and Philosophy 04 | |
| A reaction: My problem has always been that I have no idea what 'energy' is, so I'm none the wiser. |
| 3054 | Heraclitus said fire could be transformed to create the other lower elements [Heraclitus, by Diog. Laertius] |
| Full Idea: Heraclitus taught that fire when densified becomes liquid, and becoming concrete, becomes also water; again, that the water when concrete is turned to earth, and this is the road down. | |
| From: report of Heraclitus (fragments/reports [c.500 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.1.6 |
| 15660 | Logos is the source of everything, and my theories separate and explain each nature [Heraclitus] |
| Full Idea: All things come into being according to this Law ('logos'), ...and I expound theories (words) and processes (actions) separating each thing according to its nature and explaining how it is made. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B001), quoted by Sextus Empiricus - Against the Mathematicians 7.133 | |
| A reaction: I like the fact that things are separated according to their natures (particulars!), and not that natures are somehow bestowed on individuals. |
| 9363 | Science seeks classification which will discover laws, essences, and predictions [Lewis,CI] |
| Full Idea: The scientific search is for such classification as will make it possible to correlate appearance and behaviour, to discover law, to penetrate to the "essential nature" of things in order that behaviour may become predictable. | |
| From: C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.368) | |
| A reaction: Modern scientific essentialists no longer invoke scare quotes, and I think we should talk of the search for the 'mechanisms' which explain behaviour, but Lewis seems to have been sixty years ahead of his time. |
| 12269 | All things are in a state of motion [Heraclitus, by Aristotle] |
| Full Idea: All things are in a state of motion. | |
| From: report of Heraclitus (fragments/reports [c.500 BCE]) by Aristotle - Topics 104b22 | |
| A reaction: This seems right, I would say. It seems to make a 'process' the fundamental category of ontology, rather than an 'object'. |
| 420 | The cosmos is eternal not created, and is an ever-living and changing fire [Heraclitus] |
| Full Idea: This cosmos, which is the same for all, was not created by any one of the gods or of mankind, but it was ever and is and shall be ever-living fire, kindled and quenched in measure. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B030), quoted by Clement - Miscellanies 5.1.103 |
| 1499 | Heraclitus says intelligence draws on divine reason [Heraclitus, by Sext.Empiricus] |
| Full Idea: According to Heraclitus we become intelligent by drawing on divine reason. | |
| From: report of Heraclitus (fragments/reports [c.500 BCE], A16) by Sextus Empiricus - Against the Professors (six books) 7.129 |
| 15659 | Purifying yourself with blood is as crazy as using mud to wash off mud [Heraclitus] |
| Full Idea: They purify themselves by staining themselves with other blood, as if one were to step into mud to wash off mud. But a man would be thought mad if any of his fellow-men should perceive him acting thus. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B005), quoted by Origen - Against Celsus 7.62 |
| 7607 | Nagarjuna and others pronounced the world of experience to be an illusion [Nagarjuna, by Armstrong,K] |
| Full Idea: Many later Buddhists (after Nagarjuna, c.120 CE) developed a belief that everything we experience is an illusion: in the West we would call them idealists. | |
| From: report of Nagarjuna (teachings [c.120]) by Karen Armstrong - A History of God Ch.3 | |
| A reaction: This is just one step beyond Plato (who at least hung onto the immediate world as an inferior reality), and is presumably intended to motivate meditators to break out of the misery of existence into a higher realm. Personally I am against it. |
| 1501 | In their ignorance people pray to statues, which is like talking to a house [Heraclitus] |
| Full Idea: In their ignorance of the true nature of gods and heroes people pray to these statues, which is like someone holding a conversation with a house. | |
| From: Heraclitus (fragments/reports [c.500 BCE], B005), quoted by Anon (Pyth) - Theosophia Tubigensis 68 |