83 ideas
| 20910 | Everything happens necessarily, and for a reason [Democritus] |
| Full Idea: Nothing happens at random, but everything for a reason and as the effect of necessity. | |
| From: Democritus (fragments/reports [c.431 BCE], B002), quoted by Pseudo-Plutarch - On the Doctrine of the Philosophers 1.25.4 | |
| A reaction: [In Aetius 'Stob'] This remark reminds us of the link between necessity and sufficient reason. Do all reasons arise for a reason? |
| 15413 | With four tense operators, all complex tenses reduce to fourteen basic cases [Burgess] |
| Full Idea: Fand P as 'will' and 'was', G as 'always going to be', H as 'always has been', all tenses reduce to 14 cases: the past series, each implying the next, FH,H,PH,HP,P,GP, and the future series PG,G,FG,GF,F,HF, plus GH=HG implying all, FP=PF which all imply. | |
| From: John P. Burgess (Philosophical Logic [2009], 2.8) | |
| A reaction: I have tried to translate the fourteen into English, but am not quite confident enough to publish them here. I leave it as an exercise for the reader. |
| 15415 | The temporal Barcan formulas fix what exists, which seems absurd [Burgess] |
| Full Idea: In temporal logic, if the converse Barcan formula holds then nothing goes out of existence, and the direct Barcan formula holds if nothing ever comes into existence. These results highlight the intuitive absurdity of the Barcan formulas. | |
| From: John P. Burgess (Philosophical Logic [2009], 2.9) | |
| A reaction: This is my reaction to the modal cases as well - the absurdity of thinking that no actually nonexistent thing might possibly have existed, or that the actual existents might not have existed. Williamson seems to be the biggest friend of the formulas. |
| 15430 | Is classical logic a part of intuitionist logic, or vice versa? [Burgess] |
| Full Idea: From one point of view intuitionistic logic is a part of classical logic, missing one axiom, from another classical logic is a part of intuitionistic logic, missing two connectives, intuitionistic v and → | |
| From: John P. Burgess (Philosophical Logic [2009], 6.4) |
| 15431 | It is still unsettled whether standard intuitionist logic is complete [Burgess] |
| Full Idea: The question of the completeness of the full intuitionistic logic for its intended interpretation is not yet fully resolved. | |
| From: John P. Burgess (Philosophical Logic [2009], 6.9) |
| 15429 | Relevance logic's → is perhaps expressible by 'if A, then B, for that reason' [Burgess] |
| Full Idea: The relevantist logician's → is perhaps expressible by 'if A, then B, for that reason'. | |
| From: John P. Burgess (Philosophical Logic [2009], 5.8) |
| 15404 | Technical people see logic as any formal system that can be studied, not a study of argument validity [Burgess] |
| Full Idea: Among the more technically oriented a 'logic' no longer means a theory about which forms of argument are valid, but rather means any formalism, regardless of its applications, that resembles original logic enough to be studied by similar methods. | |
| From: John P. Burgess (Philosophical Logic [2009], Pref) | |
| A reaction: There doesn't seem to be any great intellectual obligation to be 'technical'. As far as pure logic is concerned, I am very drawn to the computer approach, since I take that to be the original dream of Aristotle and Leibniz - impersonal precision. |
| 15405 | Classical logic neglects the non-mathematical, such as temporality or modality [Burgess] |
| Full Idea: There are topics of great philosophical interest that classical logic neglects because they are not important to mathematics. …These include distinctions of past, present and future, or of necessary, actual and possible. | |
| From: John P. Burgess (Philosophical Logic [2009], 1.1) |
| 15421 | Classical logic neglects counterfactuals, temporality and modality, because maths doesn't use them [Burgess] |
| Full Idea: Classical logic neglects counterfactual conditionals for the same reason it neglects temporal and modal distinctions, namely, that they play no serious role in mathematics. | |
| From: John P. Burgess (Philosophical Logic [2009], 4.1) | |
| A reaction: Science obviously needs counterfactuals, and metaphysics needs modality. Maybe so-called 'classical' logic will be renamed 'basic mathematical logic'. Philosophy will become a lot clearer when that happens. |
| 15427 | The Cut Rule expresses the classical idea that entailment is transitive [Burgess] |
| Full Idea: The Cut rule (from A|-B and B|-C, infer A|-C) directly expresses the classical doctrine that entailment is transitive. | |
| From: John P. Burgess (Philosophical Logic [2009], 5.3) |
| 15403 | Philosophical logic is a branch of logic, and is now centred in computer science [Burgess] |
| Full Idea: Philosophical logic is a branch of logic, a technical subject. …Its centre of gravity today lies in theoretical computer science. | |
| From: John P. Burgess (Philosophical Logic [2009], Pref) | |
| A reaction: He firmly distinguishes it from 'philosophy of logic', but doesn't spell it out. I take it that philosophical logic concerns metaprinciples which compare logical systems, and suggest new lines of research. Philosophy of logic seems more like metaphysics. |
| 15407 | Formalising arguments favours lots of connectives; proving things favours having very few [Burgess] |
| Full Idea: When formalising arguments it is convenient to have as many connectives as possible available.; but when proving results about formulas it is convenient to have as few as possible. | |
| From: John P. Burgess (Philosophical Logic [2009], 1.4) | |
| A reaction: Illuminating. The fact that you can whittle classical logic down to two (or even fewer!) connectives warms the heart of technicians, but makes connection to real life much more difficult. Hence a bunch of extras get added. |
| 15424 | Asserting a disjunction from one disjunct seems odd, but can be sensible, and needed in maths [Burgess] |
| Full Idea: Gricean implicature theory might suggest that a disjunction is never assertable when a disjunct is (though actually the disjunction might be 'pertinent') - but the procedure is indispensable in mathematical practice. | |
| From: John P. Burgess (Philosophical Logic [2009], 5.2) | |
| A reaction: He gives an example of a proof in maths which needs it, and an unusual conversational occasion where it makes sense. |
| 15409 | All occurrences of variables in atomic formulas are free [Burgess] |
| Full Idea: All occurrences of variables in atomic formulas are free. | |
| From: John P. Burgess (Philosophical Logic [2009], 1.7) |
| 15414 | The denotation of a definite description is flexible, rather than rigid [Burgess] |
| Full Idea: By contrast to rigidly designating proper names, …the denotation of definite descriptions is (in general) not rigid but flexible. | |
| From: John P. Burgess (Philosophical Logic [2009], 2.9) | |
| A reaction: This modern way of putting it greatly clarifies why Russell was interested in the type of reference involved in definite descriptions. Obviously some descriptions (such as 'the only person who could ever have…') might be rigid. |
| 15406 | 'Induction' and 'recursion' on complexity prove by connecting a formula to its atomic components [Burgess] |
| Full Idea: There are atomic formulas, and formulas built from the connectives, and that is all. We show that all formulas have some property, first for the atomics, then the others. This proof is 'induction on complexity'; we also use 'recursion on complexity'. | |
| From: John P. Burgess (Philosophical Logic [2009], 1.4) | |
| A reaction: That is: 'induction on complexity' builds a proof from atomics, via connectives; 'recursion on complexity' breaks down to the atomics, also via the connectives. You prove something by showing it is rooted in simple truths. |
| 15425 | The sequent calculus makes it possible to have proof without transitivity of entailment [Burgess] |
| Full Idea: It might be wondered how one could have any kind of proof procedure at all if transitivity of entailment is disallowed, but the sequent calculus can get around the difficulty. | |
| From: John P. Burgess (Philosophical Logic [2009], 5.3) | |
| A reaction: He gives examples where transitivity of entailment (so that you can build endless chains of deductions) might fail. This is the point of the 'cut free' version of sequent calculus, since the cut rule allows transitivity. |
| 15426 | We can build one expanding sequence, instead of a chain of deductions [Burgess] |
| Full Idea: Instead of demonstrations which are either axioms, or follow from axioms by rules, we can have one ever-growing sequence of formulas of the form 'Axioms |- ______', where the blank is filled by Axioms, then Lemmas, then Theorems, then Corollaries. | |
| From: John P. Burgess (Philosophical Logic [2009], 5.3) |
| 15408 | 'Tautologies' are valid formulas of classical sentential logic - or substitution instances in other logics [Burgess] |
| Full Idea: The valid formulas of classical sentential logic are called 'tautologically valid', or simply 'tautologies'; with other logics 'tautologies' are formulas that are substitution instances of valid formulas of classical sentential logic. | |
| From: John P. Burgess (Philosophical Logic [2009], 1.5) |
| 15418 | Validity (for truth) and demonstrability (for proof) have correlates in satisfiability and consistency [Burgess] |
| Full Idea: Validity (truth by virtue of logical form alone) and demonstrability (provability by virtue of logical form alone) have correlative notions of logical possibility, 'satisfiability' and 'consistency', which come apart in some logics. | |
| From: John P. Burgess (Philosophical Logic [2009], 3.3) |
| 15411 | We only need to study mathematical models, since all other models are isomorphic to these [Burgess] |
| Full Idea: In practice there is no need to consider any but mathematical models, models whose universes consist of mathematical objects, since every model is isomorphic to one of these. | |
| From: John P. Burgess (Philosophical Logic [2009], 1.8) | |
| A reaction: The crucial link is the technique of Gödel Numbering, which can translate any verbal formula into numerical form. He adds that, because of the Löwenheim-Skolem theorem only subsets of the natural numbers need be considered. |
| 15412 | Models leave out meaning, and just focus on truth values [Burgess] |
| Full Idea: Models generally deliberately leave out meaning, retaining only what is important for the determination of truth values. | |
| From: John P. Burgess (Philosophical Logic [2009], 2.2) | |
| A reaction: This is the key point to hang on to, if you are to avoid confusing mathematical models with models of things in the real world. |
| 15416 | We aim to get the technical notion of truth in all models matching intuitive truth in all instances [Burgess] |
| Full Idea: The aim in setting up a model theory is that the technical notion of truth in all models should agree with the intuitive notion of truth in all instances. A model is supposed to represent everything about an instance that matters for its truth. | |
| From: John P. Burgess (Philosophical Logic [2009], 3.2) |
| 15428 | The Liar seems like a truth-value 'gap', but dialethists see it as a 'glut' [Burgess] |
| Full Idea: It is a common view that the liar sentence ('This very sentence is not true') is an instance of a truth-value gap (neither true nor false), but some dialethists cite it as an example of a truth-value glut (both true and false). | |
| From: John P. Burgess (Philosophical Logic [2009], 5.7) | |
| A reaction: The defence of the glut view must be that it is true, then it is false, then it is true... Could it manage both at once? |
| 10245 | One geometry cannot be more true than another [Poincaré] |
| Full Idea: One geometry cannot be more true than another; it can only be more convenient. | |
| From: Henri Poincaré (Science and Method [1908], p.65), quoted by Stewart Shapiro - Philosophy of Mathematics | |
| A reaction: This is the culminating view after new geometries were developed by tinkering with Euclid's parallels postulate. |
| 16146 | Two can't be a self-contained unit, because it would need to be one to do that [Democritus, by Aristotle] |
| Full Idea: Democritus claimed that one substance could not be composed from two nor two from one. …The same will clearly go for number, on the popular assumption that number is a combination of units. Unless two is one, it cannot contain a unit in actuality. | |
| From: report of Democritus (fragments/reports [c.431 BCE]) by Aristotle - Metaphysics 1039a15 | |
| A reaction: Chrysippus followed this up the first part with the memorable example of Dion and Theon. The problem with the second part is that 2, 3 and 4 are three numbers, so they can count as meta-units. |
| 20901 | True Being only occurs when it is completely full, with atoms and no void [Democritus, by Aristotle] |
| Full Idea: In response to defenders of the One, Democritus says that what is, in the proper sense, is being that is completely full, but that such a being is not one, but that they are unlimited in number and invisible because of the smallness of their masses. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A007) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 325a28 | |
| A reaction: Democritus is in a tangle here. He says proper being has no void, having apparently conceded that motion needs void (which he admits is non-existent). So true being only occurs when everything grinds to a halt, which is not now. But Idea 20902. |
| 20902 | Being does not exist more than non-being [Democritus, by Aristotle] |
| Full Idea: They say that being does not exist more than non-being, because neither does the void exist more than the body. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A006) by Aristotle - Metaphysics 0985b09 | |
| A reaction: The claim that Being and Non-Being are the same thing is pretty startling. It seems to be an expedient to get Void into the picture, even though it is taken to be wholly devoid of qualities. |
| 20904 | The non-existent exists as much as the existent, because it has causal powers [Democritus] |
| Full Idea: What exists does not exist at all more than what does not exist, and both are causes in a similar way for the things that come about. | |
| From: Democritus (fragments/reports [c.431 BCE], A008), quoted by Simplicius - On Aristotle's 'Physics' p.28.4-27 | |
| A reaction: [Simplicius actually attributes this to the shadowy Leucippus] You can see the point. If you drive into a pothole, that has considerable causal powers. |
| 20903 | The only distinctions are Configuration (shape), Disposition (order) and Turning (position) [Democritus, by Aristotle] |
| Full Idea: They say that what is differs only by Configuration ([rhusmos], which is the shape), by Disposition ([diathege], which is the order), and by Turning ([tropê], which is the position. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A006) by Aristotle - Metaphysics 0985b16 | |
| A reaction: If you give the shape, structure and position of an object, there is no much more to say. Perhaps mention time. |
| 20893 | Nothing comes from non-existence, or passes into it [Democritus, by Diog. Laertius] |
| Full Idea: Nothing comes into being from what does not exist, nor is it destroyed into what does not exist. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A001) by Diogenes Laertius - Lives of Eminent Philosophers 09.44 | |
| A reaction: [part of a concise summary of Democritus by DL] Probably an intuition about conservation laws, rather than a speculation about the Big Bang. |
| 20896 | It is not possible to know what sort each thing is [Democritus] |
| Full Idea: In reality [eteé] to recognise what sort each thing is, belongs to what is impracticable [aporos]. | |
| From: Democritus (fragments/reports [c.431 BCE], B008), quoted by Sextus Empiricus - Against the Logicians (two books) 7.137 | |
| A reaction: On the whole modern scientists (and the rest of us) shoehorn virtually everything into a specific category. It strikes me as wildly bad metaphysics to say that everything necessarily has its category. |
| 3357 | Democritus denies reality to large objects, because atomic entities can't combine to produce new ones [Benardete,JA on Democritus] |
| Full Idea: Democritus appears to rule out from his austere ontology all so-called emergent entities - even mountains and rivers - on the ground that two or more entities can never combine to produce a new one. | |
| From: comment on Democritus (fragments/reports [c.431 BCE]) by José A. Benardete - Metaphysics: the logical approach Ch.24 |
| 598 | Democritus said that substances could never be mixed, so atoms are the substances [Democritus, by Aristotle] |
| Full Idea: Democritus claimed that one substance could not be composed from two nor two from one; for him it is the atoms that are the substances. | |
| From: report of Democritus (fragments/reports [c.431 BCE]) by Aristotle - Metaphysics 1039a10 |
| 15420 | De re modality seems to apply to objects a concept intended for sentences [Burgess] |
| Full Idea: There is a problem over 'de re' modality (as contrasted with 'de dicto'), as in ∃x□x. What is meant by '"it is analytic that Px" is satisfied by a', given that analyticity is a notion that in the first instance applies to complete sentences? | |
| From: John P. Burgess (Philosophical Logic [2009], 3.9) | |
| A reaction: This is Burgess's summary of one of Quine's original objections. The issue may be a distinction between whether the sentence is analytic, and what makes it analytic. The necessity of bachelors being unmarried makes that sentence analytic. |
| 15419 | General consensus is S5 for logical modality of validity, and S4 for proof [Burgess] |
| Full Idea: To the extent that there is any conventional wisdom about the question, it is that S5 is correct for alethic logical modality, and S4 correct for apodictic logical modality. | |
| From: John P. Burgess (Philosophical Logic [2009], 3.8) | |
| A reaction: In classical logic these coincide, so presumably one should use the minimum system to do the job, which is S4 (?). |
| 15417 | Logical necessity has two sides - validity and demonstrability - which coincide in classical logic [Burgess] |
| Full Idea: Logical necessity is a genus with two species. For classical logic the truth-related notion of validity and the proof-related notion of demonstrability, coincide - but they are distinct concept. In some logics they come apart, in intension and extension. | |
| From: John P. Burgess (Philosophical Logic [2009], 3.3) | |
| A reaction: They coincide in classical logic because it is sound and complete. This strikes me as the correct approach to logical necessity, tying it to the actual nature of logic, rather than some handwavy notion of just 'true in all possible worlds'. |
| 15422 | Three conditionals theories: Materialism (material conditional), Idealism (true=assertable), Nihilism (no truth) [Burgess] |
| Full Idea: Three main theories of the truth of indicative conditionals are Materialism (the conditions are the same as for the material conditional), Idealism (identifying assertability with truth-value), and Nihilism (no truth, just assertability). | |
| From: John P. Burgess (Philosophical Logic [2009], 4.3) |
| 15423 | It is doubtful whether the negation of a conditional has any clear meaning [Burgess] |
| Full Idea: It is contentious whether conditionals have negations, and whether 'it is not the case that if A,B' has any clear meaning. | |
| From: John P. Burgess (Philosophical Logic [2009], 4.9) | |
| A reaction: This seems to be connected to Lewis's proof that a probability conditional cannot be reduced to a single proposition. If a conditional only applies to A-worlds, it is not surprising that its meaning gets lost when it leaves that world. |
| 1532 | Sensible qualities can't be real if they appear different to different creatures [Democritus, by Theophrastus] |
| Full Idea: As proof of the fact that sensible qualities have no real existence he points to the fact that they do not appear the same to all creatures. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A135) by Theophrastus - On the Senses 63 |
| 20894 | Man is separated from reality [Democritus] |
| Full Idea: It is necessary to recognise that man by virtue of this criterion is separated from reality. | |
| From: Democritus (fragments/reports [c.431 BCE], B006), quoted by Sextus Empiricus - Against the Logicians (two books) 7.137 | |
| A reaction: I don't know what 'this criterion' is, but it strikes me as quite a good slogan for fans (like myself) of the representative theory of perception. Critics say it is the big objection to the representative theory, but I say 'get over it'. |
| 20897 | Obscure knowledge belongs to the five senses, and genuine knowledge is the other type [Democritus] |
| Full Idea: There are two forms of knowledge [gnomé], the one genuine, the other obscure. And to the obscure one belongs all of these: sight, hearing, smell, taste, touch. The other is genuine, and is separated from this one. | |
| From: Democritus (fragments/reports [c.431 BCE], B011), quoted by Sextus Empiricus - Against the Logicians (two books) 7.139 | |
| A reaction: [Sextus goes on to make it clear that the 'genuine' one is knowledge acquired by thought]. I take Parmenides to be the first rationalist. It is interesting that Democritus, who devoted his life to finding causal explanations, seems to be a rationalist. |
| 517 | All evidence comes from senses, so they are indispensable to the mind [Democritus] |
| Full Idea: Mind must never reject the senses, because that is where it gets its evidence, and it would be the mind's downfall. | |
| From: Democritus (fragments/reports [c.431 BCE], B125), quoted by Galen - On Medical Experience 15.8 |
| 20895 | We actually know nothing, and opinions are mere flux [Democritus] |
| Full Idea: Certainly this argument too makes it clear that in reality [eteé] we know nothing about anything, but for each person opinion is a rhythmic afflux [epirhusmié]. | |
| From: Democritus (fragments/reports [c.431 BCE], B007), quoted by Sextus Empiricus - Against the Logicians (two books) 7.137 | |
| A reaction: This seems to pick 'all is flux' up from Heraclitus, and make Democritus (along with aspects of Socrates) the true source of ancient scepticism. |
| 1528 | We in fact know nothing, but we each restructure our reality with beliefs [Democritus] |
| Full Idea: In reality we know nothing about anything, but belief restructures things for each of us. | |
| From: Democritus (fragments/reports [c.431 BCE], B007), quoted by Sextus Empiricus - Against the Professors (six books) 7.136 |
| 492 | It is obviously impossible to understand the reality of each thing [Democritus] |
| Full Idea: It will be obvious that it is impossible to understand how in reality each thing is. | |
| From: Democritus (fragments/reports [c.431 BCE], B008), quoted by Sextus Empiricus - Against the Professors (six books) 7.137 |
| 515 | We know nothing in reality; for truth lies in an abyss [Democritus] |
| Full Idea: We know nothing in reality; for truth lies in an abyss. | |
| From: Democritus (fragments/reports [c.431 BCE], B117), quoted by Diogenes Laertius - Lives of Eminent Philosophers 09.72.10 |
| 577 | Democritus says there is either no truth, or it is concealed from us [Democritus, by Aristotle] |
| Full Idea: Democritus concludes that either there is no truth or it is concealed from us. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A112) by Aristotle - Metaphysics 1009b12 |
| 20892 | Democritus was devoted to discovering causal explanations [Democritus, by Eusebius] |
| Full Idea: Democritus himself, as they say, stated that he would rather discover a single causal explanation [aitiologia] than become the King of the Persians. | |
| From: report of Democritus (fragments/reports [c.431 BCE], B118) by Eusebius - Preparation for the Gospel 14.27.4 | |
| A reaction: Democritus seems to be clearly the father of the physical sciences, because he focused single-mindedly on physical and causal explanations. David Lewis says all explanations are causal. |
| 5882 | Democritus says soul consists of smooth round bodies brought together in accidental collision [Democritus, by Cicero] |
| Full Idea: Since Democritus makes the soul consist of minute smooth round bodies brought together in some sort of accidental collision, let us pass him over. | |
| From: report of Democritus (fragments/reports [c.431 BCE]) by M. Tullius Cicero - Tusculan Disputations I.xi.23 | |
| A reaction: If we accept that Democritus thought the collision of atoms 'accidental', then it doesn't sound like a very good theory. What would Cicero say if we replaced 'accidental' with 'naturally selected'? |
| 6034 | Atomists say soul has a rational part in the chest, and a diffused non-rational part [Democritus, by Aetius] |
| Full Idea: Democritus and Epicurus say the soul has two parts, one which is rational and is situated in the chest area, and the other which is non-rational and is spread throughout the entire compound of the body. | |
| From: report of Democritus (fragments/reports [c.431 BCE]) by Aetius - fragments/reports 4.4.6 | |
| A reaction: The spread part corresponds to such things as feeling fear in the stomach, or excitement throughout the limbs. I can't think what grounds there would be for choosing the chest as the home of reason. I suppose you can hear reason thumping in there.. |
| 20912 | The soul is the same as the mind [Democritus, by Aristotle] |
| Full Idea: Democritus says the soul is the same thing as the mind. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A101) by Aristotle - De Anima 405a10 | |
| A reaction: This is not in contrast to the Christian concept of the soul, but in contrast to the normal view of psuché, which is more like the life that permeates the whole body. Democritus was more in tune than Aristotle with modern thought on this. |
| 20916 | Animals have a share of reason [Democritus, by Porphyry] |
| Full Idea: Democritus recognised that animals have a share of reason. | |
| From: report of Democritus (fragments/reports [c.431 BCE]) by Porphyry - On Abstinence 3.6.7 | |
| A reaction: Since he considers thinking to be the interaction of atoms in the body, which animals evidently possess, this seems consistent. No one seems to observed animals closely before the 20th century, other than to exploit them. |
| 20914 | The directive centre is located in the whole head [Democritus, by Ps-Plutarch] |
| Full Idea: Democritus says [the directive centre is located] in the whole head. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A105) by Pseudo-Plutarch - On the Doctrine of the Philosophers 4.5.1 | |
| A reaction: The whole head is not quite the brain, but he is getting very warm indeed, and long before anyone else got so close. |
| 6033 | Democritus said everything happens of necessity, by natural motion of atoms [Democritus, by Cicero] |
| Full Idea: Democritus, the founder of atomism, preferred to accept that all things happened by necessity than to tear from the atomic bodies their natural motions. | |
| From: report of Democritus (fragments/reports [c.431 BCE]) by M. Tullius Cicero - On Fate ('De fato') §22 | |
| A reaction: This is in opposition to Epicurus, who said that atoms can have a 'swerve', making free will possible. It is suggested that Epicurus was the first to really grasp the problem of free will. Democritus was just stating the (to him) obvious. |
| 5088 | Some say there is a determinate cause for every apparently spontaneous event [Democritus, by Aristotle] |
| Full Idea: Some people (Democritus?) say there is no such thing as a chance event; they claim that there is always a determinate cause for everything which is said to be a chance or a spontaneous event. | |
| From: report of Democritus (fragments/reports [c.431 BCE]) by Aristotle - Physics 195b37 | |
| A reaction: This is the mutual implication of physicalism and determinism, which strikes me as unavoidable. I say: don't panic about morality because determinism is true. Embrace determinism - it is harmless and true. Its opposite is a nonsense. |
| 21670 | Democritus said atoms only move by their natural motions, which are therefore necessary [Democritus, by Cicero] |
| Full Idea: The author of the atomic theory, Democritus, preferred to accept the view that all events are caused by necessity, rather than to deprive the atoms of their natural motions. | |
| From: report of Democritus (fragments/reports [c.431 BCE]) by M. Tullius Cicero - On Fate ('De fato') 10.23 | |
| A reaction: The 'deprivation' would have to be caused by mind, or by the later 'swerve' of Epicurus. |
| 20913 | Democritus says the soul is the body, and thinking is thus the mixture of the body [Democritus, by Theophrastus] |
| Full Idea: Democritus explains thinking by the mixture of the body, which is surely in accordance with his reasoning, since he makes the soul the body. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A135) by Theophrastus - On the Senses 58 | |
| A reaction: I agree with Democritus. |
| 24041 | Democritus says spherical atoms are fire, and constitute the soul [psuche] [Democritus, by Aristotle] |
| Full Idea: Democritus says the soul is a sort of fire. For the shapes and atoms are unlimitied and those that are spherical he says are fire and soul - which are like the motes in the air when sunbeams come through the window. | |
| From: report of Democritus (fragments/reports [c.431 BCE], DK 67-68) by Aristotle - De Anima 403b31 | |
| A reaction: It's hard to see why the spherical atoms should be fire. Maybe because they move together quickly and easily. …At 404a5 Aristotle agrees with me! |
| 1540 | Pleasure and pain guide our choices of good and bad [Democritus] |
| Full Idea: The guides to what is good and bad for people are pleasure and pain. | |
| From: Democritus (fragments/reports [c.431 BCE], B188), quoted by John Stobaeus - Anthology 3.01.46 |
| 495 | Wisdom creates a healthy passion-free soul [Democritus] |
| Full Idea: Medicine heals diseases of the body, wisdom frees the soul from passions. | |
| From: Democritus (fragments/reports [c.431 BCE], B031), quoted by Clement - Pedagogue 1.6.2.1 | |
| A reaction: The interesting concept of a healthy mind seems to have got lost in modern moral philosophy. |
| 1537 | Happiness is identifying and separating the pleasures [Democritus, by Stobaeus] |
| Full Idea: Democritus thinks that happiness consists in the determination and separation of pleasures, and that this is what is both finest and most beneficial for people. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A167) by John Stobaeus - Anthology 2.07.3 | |
| A reaction: A great deal of the strategy and ethics of living consists (if you are lucky) of discriminating among possible pleasures. Philosophers should produce criteria. |
| 20917 | Contentment comes from moderation and proportion in life [Democritus, by Stobaeus] |
| Full Idea: Contentment [euthumia] comes about for human beings from the moderation of enjoyment and proportion [summetria] in life. | |
| From: report of Democritus (fragments/reports [c.431 BCE], B191) by John Stobaeus - Anthology 3.1.210 | |
| A reaction: This is close to Aristotle's doctrine of the Mean. The majority of ethical ideas attributed to Democritus (presumably by the Epicureans) are thought to be spurious. This idea actually sounds rather stoic. |
| 13551 | Democritus says wealth is a burden to the virtuous mind [Democritus, by Seneca] |
| Full Idea: Democritus rejected wealth, regarding it as a burden to the virtuous mind. | |
| From: report of Democritus (fragments/reports [c.431 BCE]) by Seneca the Younger - On Providence §6 | |
| A reaction: The rival view is that wealth empowers a virtuous person to perform more fine deeds. Democritus seems to have a rather solitary view of virtue. |
| 1525 | Atomists say there are only three differences - in shape, arrangement and position [Democritus, by Aristotle] |
| Full Idea: Democritus and Leucippus say that there are only three differences - in shape, arrangement and position. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A006) by Aristotle - Metaphysics 0985b15 |
| 493 | Experiences are merely convention; only atoms and the void are real [Democritus] |
| Full Idea: Sweet exists by convention, bitter by convention, colour by convention; atoms and void alone exist in reality. | |
| From: Democritus (fragments/reports [c.431 BCE], B009), quoted by Sextus Empiricus - Against the Logicians (two books) 7.135 |
| 17542 | 'Full' and 'Void' secularised Parmenides's Being and Not-being [Democritus, by Heisenberg] |
| Full Idea: In atomism, the antithesis of Being and Not-being of Parmenides is secularised into the antithesis of the 'Full' and the 'Void'. | |
| From: report of Democritus (fragments/reports [c.431 BCE]) by Werner Heisenberg - Physics and Philosophy 04 |
| 5947 | If only atoms are real and the rest is convention, we wouldn't bother to avoid pain [Democritus, by Diogenes of Oen.] |
| Full Idea: Democritus erred when he said that the atoms alone exist in truth among realities, but everything else is convention; for then, far from discovering the truth, we shall not even be able to live, since we shall avoid neither fire nor wounds. | |
| From: report of Democritus (fragments/reports [c.431 BCE]) by Diogenes (Oen) - fragments/reports F2 7 | |
| A reaction: The point is that we have to treat pain as a reality, not just as a convention. I suspect that Diogenes is making the same mistake made by modern attackers of 'eliminativism'. It is all about identity and reduction and levels of reality… |
| 13219 | When atoms touch, why don't they coalesce, like water drops? [Aristotle on Democritus] |
| Full Idea: Why, when they come into contact, do they [atoms] not coalesce into one, as drops of water run together when drop touches drop? | |
| From: comment on Democritus (fragments/reports [c.431 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 326a33 | |
| A reaction: Presumably we must think of atoms as having basic ontological unity, rather than as being little globules of 'stuff'. They are more like monads than they are like mud. |
| 1533 | Because appearance is infinitely varied, atomists assume infinitely many shapes of atom [Democritus, by Aristotle] |
| Full Idea: They thought that truth lay in appearances, which they appreciated are contradictory and infinite, so they made the shapes of atoms infinite. Thus the infinite changes in compounds create the infinitely varies appearances. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A009) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 315b9 |
| 20899 | Atoms cling together, until a stronger necessity disperses them [Democritus, by Aristotle] |
| Full Idea: Democritus thinks that the substances hold on to one another and remain together for a length of time until some stronger necessity arising from their surroundings shakes and disperses them. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A037) by Aristotle - On Democritus (frag) | |
| A reaction: [quoted in Simplicius, Commentary on Aristotle's On the Heavens] He's not wrong. This seems to provide a mechanism for the Heracltean flux. Ancient critics wanted to know where the 'stronger necessity' came from. |
| 20898 | Atoms are irregular, hooked, concave, convex, and many other shapes [Democritus, by Aristotle] |
| Full Idea: Some substances are irregular, others hook-shaped, other concave, other convex, others provided with innumerable other differences. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A037) by Aristotle - On Democritus (frag) | |
| A reaction: [quoted in Simplicius, Commentary on Aristotle's On the Heavens] 'Substance' here means a fundamental object, which for Democritus is an undividable atom. |
| 20908 | There could be an atom the size of the world [Democritus, by Ps-Plutarch] |
| Full Idea: Democritus say that it is possible that there exists an atom of the size of the world. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A047) by Pseudo-Plutarch - On the Doctrine of the Philosophers 1.12.6 | |
| A reaction: The editor says this may have been a criticism of Democritus - presumably a reductio ad absurdum. But Democritus has no upper limit on the size of an atom. It challenges the imagination to treat such a huge thing as indivisible. |
| 1527 | There must be atoms, to avoid the absurdity of infinite division down to nothing [Democritus, by Aristotle] |
| Full Idea: If everything is infinitely divided, what survives the divisions? Alternatively, division would end at points with no magnitude, in which case bodies are composed of nothing. This is the argument claiming there are atoms of some magnitude. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A048b) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 316a14- |
| 20909 | The basic atoms are without qualities - which only arise from encounters between atoms [Democritus, by Galen] |
| Full Idea: Democritus and the Epicureans posit that the first element is without quality, possessing by nature neither whiteness, blackness, sweetness or bitterness, warmth or cold. ...It is from the encounter of the atoms that all the sensible qualities come about. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A049) by Galen - On Hippocrates and Plato 1.2 | |
| A reaction: Idea 493 comes in the middle of this summary by Galen. Hence atoms play the role that substrates play in object-based metaphysics. So atoms have the same problem. Is the shape of an atom a quality of an atom. Or are qualities what atoms DO? |
| 1536 | If a cone is horizontally sliced the surfaces can't be equal, so it goes up in steps [Democritus] |
| Full Idea: If a cone is cut parallel to the base are the two new surfaces equal or unequal? If they are unequal, the cone must have gone up in steps. If they are equal then the cone must have been a cylinder, which is absurd. | |
| From: Democritus (fragments/reports [c.431 BCE], B155), quoted by Plutarch - 72: Against Stoics on common Conceptions 1079e1 |
| 23314 | Greeks explained regularity by intellectual design, not by laws [Democritus, by Frede,M] |
| Full Idea: It is clear that Democritus had no idea of laws of nature …for in Greek thought regularity of behaviour is associated with design by an intellect. | |
| From: report of Democritus (fragments/reports [c.431 BCE]) by Michael Frede - A Free Will Intro | |
| A reaction: Ah. A simple realisation…! Seventeenth century laws of nature offered an explanation of natural order which didn't rely on God. Even though those scientists were all theists. |
| 24059 | Democritus is wrong: in a void we wouldn't see a distant ant in exact detail [Aristotle on Democritus] |
| Full Idea: Democritus did not speak correctly in supposing that if the intermediate space became a void, we would see an ant in exact detail if it were up in the heaven. …If the intermediate space became a void, rather nothing would be seen at all. | |
| From: comment on Democritus (fragments/reports [c.431 BCE]) by Aristotle - De Anima 419a15 | |
| A reaction: Depends what you mean by void, but Aristotle is nearer the truth. Is vision clearer in outer space than in our higher atmosphere? |
| 5101 | Movement is impossible in a void, because nothing can decide the direction of movement [Aristotle on Democritus] |
| Full Idea: Void makes it impossible for anything to move, since in a void there is nowhere for a thing to move to more or less than anywhere else, because the void by definition contains no differentiation. | |
| From: comment on Democritus (fragments/reports [c.431 BCE]) by Aristotle - Physics 214b32 | |
| A reaction: A lovely application of the Principle of Sufficient Reason. However this assumes that the cause of the movement is going to be in the void (telos?), rather than in the body which will move (modern causation?). |
| 20905 | Growth and movement would not exist if there were no void to receive them [Democritus] |
| Full Idea: They say that one argument for void is that otherwise local motion (that is, locomotion and growth) would not exist: for there would not seem to be motion if there were no void, for what is full is incapable of receiving anything. | |
| From: Democritus (fragments/reports [c.431 BCE], A019), quoted by Aristotle - Physics 213b03 | |
| A reaction: The modern concept of a 'field' seems to have removed the possibility of a genuine 'void'. |
| 20911 | There are unlimited worlds of varying sizes, some without life or water [Democritus, by Hippolytus] |
| Full Idea: Democritus says that there exist unlimited worlds and that they are different in magnitude. ...Some worlds are devoid of animals and plants and of all humidity. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A010, A040) by Hippolytus - Refutation of All Heresies 1.12,13.2-4 | |
| A reaction: I'm not clear why Democritus came up with the idea of the Multicosmos. I don't suppose he meant the moon or planets, but another Cosmos. |
| 1535 | Democritus said people imagined gods as the source of what awed or frightened them [Democritus, by Sext.Empiricus] |
| Full Idea: Democritus thought that people imagined gods as responsible for the frightening and awesome things that happen in this world. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A075) by Sextus Empiricus - Against the Professors (six books) 9.24 |
| 20915 | The soul is destroyed with the body [Democritus, by Ps-Plutarch] |
| Full Idea: Democritus says the soul is destructible, and is destroyed together with the whole body. | |
| From: report of Democritus (fragments/reports [c.431 BCE], A109) by Pseudo-Plutarch - On the Doctrine of the Philosophers 4.7.4 | |
| A reaction: This is the only belief possible for Democritus, since everything, including life and soul, is just the confluence of atoms, and they are regularly dispersed. This is the epitome of materialist philosophy. |