57 ideas
| 1887 | You cannot divide anything into many parts, because after the first division you are no longer dividing the original [Sext.Empiricus] |
| Full Idea: You cannot divide anything (such as the decad) into many parts, because as soon as you separate the first part, you are no longer dividing the original. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], II.215) |
| 16539 | A definition of a circle will show what it is, and show its generating principle [Lowe] |
| Full Idea: If the definition of a circle is based on 'locus of a point', this tells us what a circle is, and it does so by revealing its generating principle, what it takes for a circle to come into being. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 6) | |
| A reaction: Lowe says that real definitions, as essences, do not always have to spell out a 'generating principle', but they do in this case. Another approach would be to try to map dependence relations between truths about circles, and see what is basic. |
| 16540 | Defining an ellipse by conic sections reveals necessities, but not the essence of an ellipse [Lowe] |
| Full Idea: Defining an ellipse in terms of the oblique intersection of a cone and a plane (rather than in terms of the sum of the distance between the foci) gives us a necessary property, but not the essence, because the terms are extrinsic to its nature. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 6) | |
| A reaction: [compressed wording] Helpful and illuminating. If you say some figure is what results when one thing intersects another, that doesn't tell you what the result actually is. Geometrical essences may be a bit vague, but they are quite meaningful. |
| 16548 | An essence is what an entity is, revealed by a real definition; this is not an entity in its own right [Lowe] |
| Full Idea: An entity's essence is just what that entity is, revealed by its real definition. This isn't a distinct entity, but either the entity itself, or (my view) no entity at all. ..We should not reify essence, as that leads to an infinite regress of essences. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 6) | |
| A reaction: The regress problem is a real one, if we wish to treat an essence as some proper and distinct part of an entity. If it is a mechanism, for example, the presumably a mechanism has an essence. No, it doesn't! Levels of explanation! |
| 16549 | Simple things like 'red' can be given real ostensive definitions [Lowe] |
| Full Idea: Is it true that we cannot say, non-circularly, what red is? We cannot find a complex synonym for it, but I think we can provide red with an ostensive real definition. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 6) | |
| A reaction: I'm not quite sure how 'real' this definition would be, if it depends on observers (some of whom may be colourblind). In what sense is this act of ostensions a 'definition'? You must distinguish the colour from the texture or shape. |
| 1885 | Proof moves from agreed premises to a non-evident inference [Sext.Empiricus] |
| Full Idea: Dogmatists define proof as "an argument which, by means of agreed premises, reveals by way of deduction a nonevident inference". | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], II.135) |
| 12196 | A valid hypothetical syllogism is 'that which does not begin with a truth and end with a falsehood' [Sext.Empiricus] |
| Full Idea: Philo (of Megara) says that a valid hypothetical syllogism is 'that which does not begin with a truth and end with a falsehood,' as for instance the syllogism 'If it is day, I converse,' when in fact it is day and I am conversing. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], II.110) | |
| A reaction: Russell endorses this, and Rumfitt quotes it as the classic case of denying that there is any modal aspect (such as 'logical necessity') involved in logical consequence. He labels it 'material or Philonian consequence'. |
| 1902 | Since Socrates either died when he was alive (a contradiction) or died when he was dead (meaningless), he didn't die [Sext.Empiricus] |
| Full Idea: If Socrates died, he died either when he lived or when he died; so he was either dead when he was alive, or he was twice dead when he was dead. So he didn't die. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.111) | |
| A reaction: One of my favourites. Of all the mysteries facing us, the one that boggles me most is how anything can happen in the 'present' moment, if the present is just the overlap point between past and future. |
| 16545 | The essence of lumps and statues shows that two objects coincide but are numerically distinct [Lowe] |
| Full Idea: It is a metaphysically necessary truth, obtaining in virtue of the essences of such objects (of what a bronze statue and a lump of bronze are) that when it exists a bronze statue coincides with a lump of bronze, which is numerically distinct from it. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 6) | |
| A reaction: I think it is nonsense to treat the lump and statue as two objects. It is essential that a statue be made of a lump, and essential that a lump have a shape, so to treat the lump and the shape as two different objects is a failure to grasp the essence. |
| 16546 | The essence of a bronze statue shows that it could be made of different bronze [Lowe] |
| Full Idea: It is a metaphysical possibility, obtaining in virtue of the essences of such objects, that the same bronze statue should coincide with different lumps of bronze at different times. (..they have different persistence conditions). | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 6) | |
| A reaction: If the fame of a statue were that it had been made by melting down the shield of Achilles (say), then the bronze it was made of would be its most important feature. Essences are more contextual than Lowe might wish. |
| 16551 | Grasping an essence is just grasping a real definition [Lowe] |
| Full Idea: All that grasping an essence amounts to is understanding a real definition, that is, understanding a special kind of proposition. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 7) | |
| A reaction: He refuses to 'reify' an essence, and says it is not an entity, so he seems to think that the definition is the essence, but Aristotle and I take the essence to be what is picked out by the correct definition - not the definition itself. |
| 16542 | Explanation can't give an account of essence, because it is too multi-faceted [Lowe] |
| Full Idea: Explanation is a multifaceted one, with many species (logical, mathematical, causal, teleological, and psychological), ..so it is not a notion fit to be appealed to in order to frame a perspicuous account of essence. That is one species of explanation. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 6) | |
| A reaction: This directly attacks the core of my thesis! His parenthetical list does not give types of explanation. If I say this explanation is 'psychological', that says nothing about what explanation is. All of his instances could rest on essences. |
| 16552 | If we must know some entity to know an essence, we lack a faculty to do that [Lowe] |
| Full Idea: If knowledge of essence were by acquaintance of a special kind of entity, we would doubt our ability to grasp the essence of things. For what faculty could be involved in this special kind of acquaintance? | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 7) | |
| A reaction: This is Lockean empirical scepticism about essences, but I take the view that sometimes you can be acquainted with an essence, but more often you correctly infer it from you acquaintance - and this is just what scientists do. |
| 16533 | Logical necessities, based on laws of logic, are a proper sub-class of metaphysical necessities [Lowe] |
| Full Idea: If logically necessary truths are consequences of the laws of logic, then I think they are only a proper sub-class of the class of metaphysically necessary truths. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 1) | |
| A reaction: The problem for this is unusual and bizarre systems of logic, or systems that contradict one another. This idea is only plausible if you talk about the truths derived from some roughly 'classical' core of logic. 'Tonk' won't do it! |
| 16531 | 'Metaphysical' necessity is absolute and objective - the strongest kind of necessity [Lowe] |
| Full Idea: By 'metaphysical' necessity I mean necessity of the strongest possible kind - absolute necessity - and I take it to be an objective kind of necessity, rather than being something mind-dependent. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 1) | |
| A reaction: See Bob Hale for the possibility that 'absolute' and 'metaphysical' necessity might come apart. I think I believe in metaphysical necessity, but I'm uneasy about 'absolute' necessity. That may be discredited by the sceptics. |
| 16532 | 'Epistemic' necessity is better called 'certainty' [Lowe] |
| Full Idea: 'Epistemic' necessity is more properly to be called 'certainty'. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 1) | |
| A reaction: Sounds wrong. Surely I can be totally certain of a contingent truth? |
| 16543 | If an essence implies p, then p is an essential truth, and hence metaphysically necessary [Lowe] |
| Full Idea: If we can truly affirm that it is part of the essence of some entity that p is the case, then p is an essential truth and so a metaphysically necessary truth. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 6) | |
| A reaction: This feels too quick. He is trying to expound the idea (which I like) that necessity derives from essences, and not vice versa. Is it a metaphysical necessity that there are no moths in my wardrobe, because mothballs have driven them away? Maybe. |
| 16544 | Metaphysical necessity is either an essential truth, or rests on essential truths [Lowe] |
| Full Idea: A metaphysically necessary truth is a truth which is either an essential truth or a truth that obtains in virtue of the essences of two or more distinct things. Hence all metaphysical necessity is grounded in essence. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 6) | |
| A reaction: Lowe is endeavouring to give an exposition of the approach advocated by Kit Fine. I divide necessities 'because of' things (such as essences) from necessities 'for' things, such as situations or events. |
| 16538 | We could give up possible worlds if we based necessity on essences [Lowe] |
| Full Idea: If we explicate the notion of metaphysical necessity in terms of the notion of essence, rather than vice versa, this may enable us to dispense with the language of possible worlds as a means of explicating modal statements. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 6) | |
| A reaction: This is the approach I favour, though I am not convinced that the two approaches are in competition, since essentialism gives the driving force for necessity, whereas possible worlds map the logic and semantics of it. |
| 1889 | If an argument has an absurd conclusion, we should not assent to the absurdity, but avoid the absurd argument [Sext.Empiricus] |
| Full Idea: If an argument leads to confessedly absurd conclusions, we should not assent to the absurdity just because of the argument, but avoid the argument because of the absurdity. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], II.252) | |
| A reaction: cf. G.E.Moore. Denying that you have a hand seems to be an absurdity, but I'm not sure if I can give a criterion for absurdity in such a case. One person's modus ponens is another person's modus tollens. |
| 1871 | Whether honey is essentially sweet may be doubted, as it is a matter of judgement rather than appearance [Sext.Empiricus] |
| Full Idea: Honey appears to sceptics to be sweet, but whether it is also sweet in its essence is for us a matter of doubt, since this is not an appearance but a judgement. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], I.20) |
| 1883 | How can the intellect know if sensation is reliable if it doesn't directly see external objects? [Sext.Empiricus] |
| Full Idea: Just as you can't know if a portrait of Socrates is good without seeing the man, so when the intellect gazes on sensations but not the external objects it cannot know whether they are similar. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], II.75) |
| 1890 | We distinguish ambiguities by seeing what is useful [Sext.Empiricus] |
| Full Idea: It is the experience of what is useful in each affair that brings about the distinguishing of ambiguities. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], II.258) |
| 16534 | 'Intuitions' are just unreliable 'hunches'; over centuries intuitions change enormously [Lowe] |
| Full Idea: I suspect that 'intuitions' and 'hunches' are pretty much the same thing, and pretty useless as sources of knowledge. …Things that seemed intuitively true to our forebears a century or two ago often by no means seem intuitively true to us now. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 2) | |
| A reaction: I don't accept this. Intuitions change a lot over the centuries because the reliable knowledge which informs intuitions has also changed a lot. Arguments and evidence may nail individual truths, but coherence must rest on intuition. |
| 1870 | The basis of scepticism is the claim that every proposition has an equal opposing proposition [Sext.Empiricus] |
| Full Idea: The main basic principle of the sceptic system is that of opposing to every proposition an equal proposition. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], I.12) |
| 1872 | The same tower appears round from a distance, but square close at hand [Sext.Empiricus] |
| Full Idea: The same tower appears round from a distance, but square close at hand. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], I.32) |
| 1882 | The necks of doves appear different in colour depending on the angle of viewing [Sext.Empiricus] |
| Full Idea: The necks of doves appear different in hue according to the differences in the angle of inclination. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], I.120) |
| 1881 | The same oar seems bent in water and straight when out of it [Sext.Empiricus] |
| Full Idea: The same oar seems bent when in the water but straight when out of the water. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], I.119) |
| 1873 | If we press the side of an eyeball, objects appear a different shape [Sext.Empiricus] |
| Full Idea: When we press the eyeball at one side the forms, figures and sizes of the objects appear oblong and narrow. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], I.47) |
| 1874 | How can we judge between our impressions and those of other animals, when we ourselves are involved? [Sext.Empiricus] |
| Full Idea: We cannot judge between our own impressions and those of other animals, because we ourselves are involved in the dispute. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], I.59) |
| 1880 | Some actions seem shameful when sober but not when drunk [Sext.Empiricus] |
| Full Idea: Actions which seem shameful to us when sober do not seem shameful when drunk. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], I.109) |
| 1879 | Sickness is perfectly natural to the sick, so their natural perceptions should carry some weight [Sext.Empiricus] |
| Full Idea: Health is natural for the healthy but unnatural for the sick, and sickness is unnatural for the healthy but natural for the sick, so we must give credence to the natural perceptions of the sick. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], I.103) |
| 1876 | If we enjoy different things, presumably we receive different impressions [Sext.Empiricus] |
| Full Idea: The enjoyment of different things is an indication that we get varying impressions from the underlying objects. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], I.80) |
| 1878 | Water that seems lukewarm can seem very hot on inflamed skin [Sext.Empiricus] |
| Full Idea: The same water which seems very hot when poured on inflamed spots seems lukewarm to us. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], I.101) |
| 1877 | If we had no hearing or sight, we would assume no sound or sight exists, so there may be unsensed qualities [Sext.Empiricus] |
| Full Idea: A man with touch, taste and smell, but no hearing or sight, will assume nothing audible or visible exists, so maybe an apple has qualities which we have no senses to perceive. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], I.96) |
| 1910 | With us it is shameful for men to wear earrings, but among Syrians it is considered noble [Sext.Empiricus] |
| Full Idea: It is a shameful thing with us for men to wear earrings, but among some of the barbarians, such as the Syrians, it is a token of nobility. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.203) |
| 1911 | Even if all known nations agree on a practice, there may be unknown nations which disagree [Sext.Empiricus] |
| Full Idea: Even among practices on which all known cultures are agreed, disagreement about them may possibly exist amongst some of the nations which are unknown to us. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.234) |
| 1886 | If you don't view every particular, you may miss the one which disproves your universal induction [Sext.Empiricus] |
| Full Idea: Induction cannot establish the universal by means of the particular, since limited particulars may omit crucial examples which disprove the universal, and infinite particulars are impossible to know. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], II.204) |
| 1884 | If we utter three steps of a logical argument, they never exist together [Sext.Empiricus] |
| Full Idea: If we say "If day exists, lights exists", and then "day exists", and then "light exists", then parts of the judgement never exist together, and so the whole judgement will have no real existence. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], II.109) |
| 16535 | A concept is a way of thinking of things or kinds, whether or not they exist [Lowe] |
| Full Idea: The nearest I can get to a quick definition is to say that a concept is a way of thinking of some thing or kind of things, whether or not a really existent thing or kind of things. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 2) | |
| A reaction: The focus on 'things' seems rather narrow. Are relations things? He makes concepts sound adverbial, so that there is thinking going on, and then we add 'ways' of doing it. Thinking depends on concepts, not concepts on thinking. |
| 16550 | Direct reference doesn't seem to require that thinkers know what it is they are thinking about [Lowe] |
| Full Idea: It may be objected that currently prevailing causal or 'direct' theories of reference precisely deny that a thinker must know what it is the he or she is thinking about in order to be able to think about it. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 7) | |
| A reaction: Lowe says that at least sometimes we have to know that we are thinking about, so this account of reference can't be universally true. My solution is to pull identity and essence apart. You only need identity, not essence, for reference. |
| 468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
| Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
| From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |
| 1894 | Some say that causes are physical, some say not [Sext.Empiricus] |
| Full Idea: Some affirm cause to be corporeal, some incorporeal. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.14) |
| 1897 | Knowing an effect results from a cause means knowing that the cause belongs with the effect, which is circular [Sext.Empiricus] |
| Full Idea: To know an effect belongs to a cause, we must also know that that cause belongs to that effect, and this is circular. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.21) |
| 1898 | Cause can't exist before effect, or exist at the same time, so it doesn't exist [Sext.Empiricus] |
| Full Idea: If cause neither subsists before its effect, nor subsists along with it, nor does the effect precede the cause, it would seem that it has no substantial existence at all. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.27) |
| 1896 | If there were no causes then everything would have been randomly produced by everything [Sext.Empiricus] |
| Full Idea: If causes were non-existent everything would have been produced by everything, and at random. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.18) |
| 1895 | Causes are either equal to the effect, or they link equally with other causes, or they contribute slightly [Sext.Empiricus] |
| Full Idea: The majority say causes are immediate (when they are directly proportional to effects), or associate (making an equal contribution to effects), or cooperant (making a slight contribution). | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.15) |
| 16547 | H2O isn't necessary, because different laws of nature might affect how O and H combine [Lowe] |
| Full Idea: It is not metaphysically necessary that water is composed of H2O molecules, because the natural laws governing the chemical behaviour of hydrogen and oxygen atoms could have been significantly different, so they might not have composed that substance. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 6) | |
| A reaction: I fear this may be incoherent, as science. See Bird on why salt must dissolve in water. There can't (I suspect) be a law which keeps O and H the same, and yet makes them combine differently. |
| 1900 | If time and place are infinitely divided, it becomes impossible for movement ever to begin [Sext.Empiricus] |
| Full Idea: If bodies, and the places and times when they are said to move, are divided into infinity, motion will not occur, it being impossible to find anything which will initiate the first movement. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.76) |
| 1901 | If all atoms, times and places are the same, everything should move with equal velocity [Sext.Empiricus] |
| Full Idea: If objects are reducible to atoms, and each thing passes in an atomic time with its own first atom into an atomic point of space, then all moving things are of equal velocity. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.77) |
| 1899 | Does the original self-mover push itself from behind, or pull itself from in front? [Sext.Empiricus] |
| Full Idea: Self-movement must move in some particular direction, but if it pushes it will be behind itself, and if it pulls it will be in front of itself. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.68) | |
| A reaction: This is the same as Aquinas's First Way of proving God's existence. |
| 1903 | If motion and rest are abolished, so is time [Sext.Empiricus] |
| Full Idea: Since time does not seem to subsist without motion or even rest, if motion is abolished, and likewise rest, time is abolished. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.141) |
| 1904 | Time must be unlimited, but past and present can't be non-existent, and can't be now, so time does not exist [Sext.Empiricus] |
| Full Idea: There can't be a time when there was no time, so time is not limited; but unlimited time means past and present are non-existent (so time is limited to the present), or they exist (which means they are present). Time does not exist. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.142) |
| 1905 | How can time be divisible if we can't compare one length of time with another? [Sext.Empiricus] |
| Full Idea: Time is clearly divisible (into past, present and future), but it can't be, because a divisible thing is measured by some part of itself (divisions of length), but the two parts must coincide to make the measurement (e.g. present must coincide with past). | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.143) |
| 1891 | How can we agree on the concept of God, unless we agree on his substance or form or place? [Sext.Empiricus] |
| Full Idea: How shall we be able to reach a conception of God when we have no agreement about his substance or his form or his place of abode? | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.3) |
| 1892 | The existence of God can't be self-evident or everyone would have agreed on it, so it needs demonstration [Sext.Empiricus] |
| Full Idea: The existence of God is not pre-evident, for if it was the dogmatists would have agreed about it, whereas their disagreements show it is non-evident, and in need of demonstration. | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.6) |
| 1893 | If God foresaw evil he would presumably prevent it, and if he only foresees some things, why those things? [Sext.Empiricus] |
| Full Idea: If God had forethought for all, there would be no evil in the world, yet they say the world is full of evil. And if he forethinks some things, why those and not others? | |
| From: Sextus Empiricus (Outlines of Pyrrhonism [c.180], III.9) |