50 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. |
| 18806 | Frege thought traditional categories had psychological and linguistic impurities [Frege, by Rumfitt] |
| Full Idea: Frege rejected the traditional categories as importing psychological and linguistic impurities into logic. | |
| From: report of Gottlob Frege (Function and Concept [1891]) by Ian Rumfitt - The Boundary Stones of Thought 1.2 | |
| A reaction: Resisting such impurities is the main motivation for making logic entirely symbolic, but it doesn't follow that the traditional categories have to be dropped. |
| 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. |
| 8490 | First-level functions have objects as arguments; second-level functions take functions as arguments [Frege] |
| Full Idea: Just as functions are fundamentally different from objects, so also functions whose arguments are and must be functions are fundamentally different from functions whose arguments are objects. The latter are first-level, the former second-level, functions. | |
| From: Gottlob Frege (Function and Concept [1891], p.38) | |
| A reaction: In 1884 he called it 'second-order'. This is the standard distinction between first- and second-order logic. The first quantifies over objects, the second over intensional entities such as properties and propositions. |
| 8492 | Relations are functions with two arguments [Frege] |
| Full Idea: Functions of one argument are concepts; functions of two arguments are relations. | |
| From: Gottlob Frege (Function and Concept [1891], p.39) | |
| A reaction: Nowadays we would say 'two or more'. Another interesting move in the aim of analytic philosophy to reduce the puzzling features of the world to mathematical logic. There is, of course, rather more to some relations than being two-argument functions. |
| 8487 | Arithmetic is a development of logic, so arithmetical symbolism must expand into logical symbolism [Frege] |
| Full Idea: I am of the opinion that arithmetic is a further development of logic, which leads to the requirement that the symbolic language of arithmetic must be expanded into a logical symbolism. | |
| From: Gottlob Frege (Function and Concept [1891], p.30) | |
| A reaction: This may the the one key idea at the heart of modern analytic philosophy (even though logicism may be a total mistake!). Logic and arithmetical foundations become the master of ontology, instead of the servant. The jury is out on the whole enterprise. |
| 18899 | Frege takes the existence of horses to be part of their concept [Frege, by Sommers] |
| Full Idea: Frege regarded the existence of horses as a property of the concept 'horse'. | |
| From: report of Gottlob Frege (Function and Concept [1891]) by Fred Sommers - Intellectual Autobiography 'Realism' |
| 4028 | Frege allows either too few properties (as extensions) or too many (as predicates) [Mellor/Oliver on Frege] |
| Full Idea: Frege's theory of properties (which he calls 'concepts') yields too few properties, by identifying coextensive properties, and also too many, by letting every predicate express a property. | |
| From: comment on Gottlob Frege (Function and Concept [1891]) by DH Mellor / A Oliver - Introduction to 'Properties' §2 | |
| A reaction: Seems right; one extension may have two properties (have heart/kidneys), two predicates might express the same property. 'Cutting nature at the joints' covers properties as well as objects. |
| 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. |
| 8489 | The concept 'object' is too simple for analysis; unlike a function, it is an expression with no empty place [Frege] |
| Full Idea: I regard a regular definition of 'object' as impossible, since it is too simple to admit of logical analysis. Briefly: an object is anything that is not a function, so that an expression for it does not contain any empty place. | |
| From: Gottlob Frege (Function and Concept [1891], p.32) | |
| A reaction: Here is the core of the programme for deriving our ontology from our logic and language, followed through by Russell and Quine. Once we extend objects beyond the physical, it becomes incredibly hard to individuate them. |
| 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 |
| 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 |
| 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 |
| 9947 | Concepts are the ontological counterparts of predicative expressions [Frege, by George/Velleman] |
| Full Idea: Concepts, for Frege, are the ontological counterparts of predicative expressions. | |
| From: report of Gottlob Frege (Function and Concept [1891]) by A.George / D.J.Velleman - Philosophies of Mathematics Ch.2 | |
| A reaction: That sounds awfully like what many philosophers call 'universals'. Frege, as a platonist (at least about numbers), I would take to be in sympathy with that. At least we can say that concepts seem to be properties. |
| 10319 | An assertion about the concept 'horse' must indirectly speak of an object [Frege, by Hale] |
| Full Idea: Frege had a notorious difficulty over the concept 'horse', when he suggests that if we wish to assert something about a concept, we are obliged to proceed indirectly by speaking of an object that represents it. | |
| From: report of Gottlob Frege (Function and Concept [1891], Ch.2.II) by Bob Hale - Abstract Objects | |
| A reaction: This sounds like the thin end of a wedge. The great champion of objects is forced to accept them here as a façon de parler, when elsewhere they have ontological status. |
| 8488 | A concept is a function whose value is always a truth-value [Frege] |
| Full Idea: A concept in logic is closely connected with what we call a function. Indeed, we may say at once: a concept is a function whose value is always a truth-value. ..I give the name 'function' to what is meant by the 'unsaturated' part. | |
| From: Gottlob Frege (Function and Concept [1891], p.30) | |
| A reaction: So a function becomes a concept when the variable takes a value. Problems arise when the value is vague, or the truth-value is indeterminable. |
| 9948 | Unlike objects, concepts are inherently incomplete [Frege, by George/Velleman] |
| Full Idea: For Frege, concepts differ from objects in being inherently incomplete in nature. | |
| From: report of Gottlob Frege (Function and Concept [1891]) by A.George / D.J.Velleman - Philosophies of Mathematics Ch.2 | |
| A reaction: This is because they are 'unsaturated', needing a quantified variable to complete the sentence. This could be a pointer towards Quine's view of properties, as simply an intrinsic feature of predication about objects, with no separate identity. |
| 4972 | I may regard a thought about Phosphorus as true, and the same thought about Hesperus as false [Frege] |
| Full Idea: From sameness of meaning there does not follow sameness of thought expressed. A fact about the Morning Star may express something different from a fact about the Evening Star, as someone may regard one as true and the other false. | |
| From: Gottlob Frege (Function and Concept [1891], p.14) | |
| A reaction: This all gets clearer if we distinguish internalist and externalist theories of content. Why take sides on this? Why not just ask 'what is in the speaker's head?', 'what does the sentence mean in the community?', and 'what is the corresponding situation?' |
| 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). |
| 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. |
| 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'. |
| 19384 | Space and time are the order of all possibilities, and don't just relate to what is actual [Leibniz] |
| Full Idea: Space and time taken together constitute the order of possibilities of the one entire universe, so that these orders relate not only to what actually is, but also to anything that could be put in its place. | |
| From: Gottfried Leibniz (Reply to 'Rorarius' 2nd ed [1702], GP iv 568), quoted by Richard T.W. Arthur - Leibniz 7 'Space and Time' | |
| A reaction: A very nice idea. Rather like the 'space of reasons', where all rational thought must exist, space and time are the 'space of existence and action'. Their concepts involve more than relations between what actually exists. |
| 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 |
| 8491 | The Ontological Argument fallaciously treats existence as a first-level concept [Frege] |
| Full Idea: The ontological proof of God's existence suffers from the fallacy of treating existence as a first-level concept. | |
| From: Gottlob Frege (Function and Concept [1891], p.38 n) | |
| A reaction: [See Idea 8490 for first- and second-order functions] This is usually summarised as the idea that existence is a quantifier rather than a predicate. |
| 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 |
| 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 |