113 ideas
6575 | Philosophy may never find foundations, and may undermine our lives in the process [Fogelin] |
Full Idea: Not only is traditional philosophy incapable of discovering the foundations it seeks, but the philosophical enterprise may itself dislodge the contingent, de facto supports that our daily life depends upon. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.2) | |
A reaction: In the end Fogelin is not so pessimistic, but he is worried by the concern of philosophers with paradox and contradiction. I don't remotely consider this a reason to reject philosophy, but it might be a reason to keep it sealed off from daily life. |
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) |
22764 | Ordinary speech is not exact about what is true; we say we are digging a well before the well exists [Sext.Empiricus] |
Full Idea: We must allow ordinary speech to use inexact terms, as it does not seek after what is really true but what is supposed to be true. We speak of digging a well or weaving a cloak, but there is no well or cloak when they are being dug or woven. | |
From: Sextus Empiricus (Against the Logicians (two books) [c.180], II.129) | |
A reaction: Nice examples. The imprecision is reduced if I say I am creating a well, because that implies something that is not yet complete. If I say I intend to dig a well, is that imprecise because the well does not exist? |
6585 | Rationality is threatened by fear of inconsistency, illusions of absolutes or relativism, and doubt [Fogelin] |
Full Idea: The three main threats to our rational lives are fear of inconsistency, illusions (of absolutism and relativism) and doubt. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.4) | |
A reaction: This is a very nice analysis of the forces that can destroy the philosopher's aspiration to the rational life. Personally I still suffer from a few illusions about the possibility of absolutes, but I may grow out of it. The other three don't bother me. |
6568 | A game can be played, despite having inconsistent rules [Fogelin] |
Full Idea: The presence of an inconsistency in the rules that govern a game need not destroy the game. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.2) | |
A reaction: He only defends this thesis if the inconsistency is away from the main centre of the action. You can't have an inconsistent definition of scoring a goal or a touchdown. |
22752 | Reasoning is impossible without a preconception [Sext.Empiricus] |
Full Idea: It is not possible either to seek or to doubt without a preconception. | |
From: Sextus Empiricus (Against the Ethicists (one book) [c.180], II.22) | |
A reaction: [Sextus quotes this from 'the sapient Epicurus'] I think this may be a message across the centuries to Hegel, who attempted this impossible feat. My picture of philosophy is a continual shift of the preconceptions, to explore thoroughly. |
6557 | Humans may never be able to attain a world view which is both rich and consistent [Fogelin] |
Full Idea: It might be wholly unreasonable to suppose that human beings will ever be able to attain a view of the world that is both suitably rich and completely consistent. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Intro) | |
A reaction: Fogelin's lectures develop this view very persuasively. I think all philosophers must believe that the gods could attain a 'rich and consistent' view. Our problem is that we are a badly organised team, whose members keep dying. |
6560 | The law of noncontradiction is traditionally the most basic principle of rationality [Fogelin] |
Full Idea: Traditionally many philosophers (Aristotle among them) have considered the law of noncontradiction to be the deepest, most fundamental principle of rationality. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.1) | |
A reaction: For Aristotle, see Idea 1601 (and 'Metaphysics' 1005b28). The only denier of the basic character of the law that I know of is Nietzsche (Idea 4531). Fogelin, despite many qualifications, endorses the law, and so do I. |
6565 | The law of noncontradiction makes the distinction between asserting something and denying it [Fogelin] |
Full Idea: People who reject the law of noncontradiction obliterate any significant difference between asserting something and denying it; …this will not move anyone who genuinely opts either for silence or for madness. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.1) | |
A reaction: This seems a sufficiently firm and clear assertion of the basic nature of this law. The only rival view seems to be that of Nietzsche (Idea 4531), but then you wonder how Nietzsche is in a position to assert the relativity of the law. |
6574 | Legal reasoning is analogical, not deductive [Fogelin] |
Full Idea: There is almost universal agreement that legal reasoning is fundamentally analogical, not deductive, in character. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.2) | |
A reaction: This raises the question of whether analogy can be considered as 'reasoning' in itself. How do you compare the examples? Could you compare two examples if you lacked language, or rules, or a scale of values? |
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) |
6021 | It is only when we say a proposition that we speak truly or falsely [Sext.Empiricus] |
Full Idea: It is only when we say a proposition that we speak truly or falsely. | |
From: Sextus Empiricus (Against the Professors (six books) [c.180], 8.74) | |
A reaction: This makes assertions truth-bearers, rather than propositions. But a proposition can be true or false if it is stamped with a date and/or place. "Shakespeare was born in Stratford on 23rd April 1664". No one needs to assert that. |
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'. |
6020 | 'Man is a rational mortal animal' is equivalent to 'if something is a man, that thing is a rational mortal animal' [Sext.Empiricus] |
Full Idea: Definitions are identical to universal propositions in meaning, and only differ in syntax, for whoever says 'Man is a rational mortal animal' says the same thing in meaning as whoever says 'If something is a man, that thing is a rational mortal animal'. | |
From: Sextus Empiricus (Against the Professors (six books) [c.180], 11.8) | |
A reaction: How strikingly like Bertrand Russell's interest and solutions. Sextus shows a straightforward interest in logical form, of a kind we associate with the twentieth century. Did Sextus Empiricus invent quantification? |
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. |
22744 | Parts are not parts if their whole is nothing more than the parts [Sext.Empiricus] |
Full Idea: If the whole is nothing more than the sum of the parts, the parts will not be parts. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.343) | |
A reaction: Nice. Bricks lying on the ground are not parts of a wall. For them to be parts of a wall there has to be a wall which is not just the bricks. Nihilists like Van Inwagen can deny the wall in ontology, but in thought we need walls. Conceptual dependence. |
22762 | Some properties are inseparable from a thing, such as the length, breadth and depth of a body [Sext.Empiricus] |
Full Idea: Some properties are inseparable from the things to which they belong - as are length, breadth and depth from bodies, for without their presence it is impossible to perceive Body. | |
From: Sextus Empiricus (Against the Logicians (two books) [c.180], I.270) | |
A reaction: For the opposite case he suggests a man running, talking or sleeping. He doesn't mention essential natures, but this is clearly correct. We might say that they are properties which need to be mentioned in a full definition. |
6582 | Conventions can only work if they are based on something non-conventional [Fogelin] |
Full Idea: Convention, to exist at all, must have a basis in something that is not conventional; conventions, to work, need something nonconventional to build upon and shape. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.3) | |
A reaction: Fogelin attributes his point to Hume. I agree entirely. No convention could ever possibly catch on in a society unless there were some point to it. If you can't see a point to a convention (like wearing ties) then start looking, because it's there. |
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) |
22748 | Some say motion is perceived by sense, but others say it is by intellect [Sext.Empiricus] |
Full Idea: Some assert that motion is perceived by sense, but others that it is not perceived at all by sense but by the intellect through sensation. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], II.062) | |
A reaction: Descartes' wax argument defends the idea that change is perceived by intellect. The intellect has to distinguish the relative aspect of each motion, such as when someone is walking around on a moving ship. Even sense also need memory. |
6576 | My view is 'circumspect rationalism' - that only our intellect can comprehend the world [Fogelin] |
Full Idea: My own view might be called 'circumspect rationalism' - the view that our intellectual faculties provide our only means for comprehending the world in which we find oruselves. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.3) | |
A reaction: He needs to say more than that to offer a theory, but I like the label, and it fits the modern revival of rationalism, with which I sympathise, and which rests, I think, on Russell's point that self-evidence comes in degrees, not as all-or-nothing truth. |
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) |
22759 | Fools, infants and madmen may speak truly, but do not know [Sext.Empiricus] |
Full Idea: The fool and the infant and the madman at times say something true, but they do not possess knowledge of the true. | |
From: Sextus Empiricus (Against the Logicians (two books) [c.180], I.042) | |
A reaction: This may be correct of someone who is insane, but seems unfair to the fool and the infant. At what age do children begin to know things? If speech was just random nonsense, an accidental truth seems impossible. |
6589 | Knowledge is legitimate only if all relevant defeaters have been eliminated [Fogelin] |
Full Idea: In general a knowledge claim is legitimate only if all relevant defeaters have been eliminated. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.4) | |
A reaction: The problem here is what is 'relevant'. Fogelin's example is 'Are you sure the suspect doesn't have a twin brother?' If virtual reality is relevant, most knowledge is defeated. Certainly, imaginative people feel that they know less than others. |
20795 | Some things are their own criterion, such as straightness, a set of scales, or light [Sext.Empiricus] |
Full Idea: Dogmatists say something can be its own criterion. The straight is the standard of itself, and a set of scales establishes the equality of other things and of itself, and light seems to reveal not just other things but also itself. | |
From: Sextus Empiricus (Against the Mathematicians [c.180], 442) | |
A reaction: Each of these may be a bit dubious, but deserves careful discussion. |
6596 | For coherentists, circularity is acceptable if the circle is large, rich and coherent [Fogelin] |
Full Idea: Coherentists argue that if the circle of justifications is big enough, rich enough, coherent enough, and so on, then there is nothing wrong circularity. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.4) | |
A reaction: There must always be something wrong with circularity, and no god would put up with it, but we might have to. Of course, two pieces of evidence might be unconnected, such as an equation and an observation. |
22760 | Madmen are reliable reporters of what appears to them [Sext.Empiricus] |
Full Idea: The madman is a trustworthy criterion of the appearances which occur in madness. | |
From: Sextus Empiricus (Against the Logicians (two books) [c.180], I.062) | |
A reaction: It is hard to conceive of an genuinely insane person deliberately misreporting their hallucinations. They are, of course, the sole witness. |
6597 | A rule of justification might be: don't raise the level of scrutiny without a good reason [Fogelin] |
Full Idea: One rule for the justification of knowledge might be: Do not raise the level of scrutiny in the absence of a particular reason that triggers it. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.4) | |
A reaction: That won't decide the appropriate level of scrutiny from which to start. One of my maxims is 'don't set the bar too high', but it seems tough that one should have to justify moving it. The early scientists tried raising it, and were amazed by the results. |
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) |
6588 | Scepticism is cartesian (sceptical scenarios), or Humean (future), or Pyrrhonian (suspend belief) [Fogelin] |
Full Idea: The three forms of scepticism are cartesian, Humean and Pyrrhonian. The first challenges belief by inventing sceptical scenarios; the second doubts the future; the third aims to suspend belief. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.4) | |
A reaction: A standard distinction is made between methodological and global scepticism. The former seems to be Cartesian, and the latter Pyrrhonian. The interest here is see Hume placed in a distinctive category, because of his views on induction. |
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) |
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) |
20794 | How can sceptics show there is no criterion? Weak without, contradiction with [Sext.Empiricus] |
Full Idea: The dogmatists ask how the sceptic can show there is no criterion. If without a criterion, he is untrustworthy; with a criterion he is turned upside down. He says there is no criterion, but accepts a criterion to establish this. | |
From: Sextus Empiricus (Against the Mathematicians [c.180], 440) | |
A reaction: This is also the classic difficulty for foundationalist views of knowledge. Is the foundation justified, or not? |
6590 | Scepticism deals in remote possibilities that are ineliminable and set the standard very high [Fogelin] |
Full Idea: Sceptical scenarios deal in wildly remote defeating possibilities, so that the level of scrutiny becomes unrestrictedly high, and they also usually deal with defeators that are in principle ineliminable. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.4) | |
A reaction: The question of how high we 'set the bar' seems to me central to epistemology. There is clearly an element of social negotiation involved, centring on what is appropriate. If, though, scepticism is 'ineliminable', we must face up to that. |
6583 | Radical perspectivism replaces Kant's necessary scheme with many different schemes [Fogelin] |
Full Idea: We reach radical perspectivism by replacing Kant's single, necessary categorial scheme with a plurality of competing categorial schemes. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.3) | |
A reaction: It certainly looks as if Kant sent us down a slippery slope into the dafter aspects of twentieth century relativism. The best antidote I know of is Davidson's (e.g. Idea 6398). But then it seems unimaginative to say that only one scheme is possible. |
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) |
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) |
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) |
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) |
6026 | How can you investigate without some preconception of your object? [Sext.Empiricus] |
Full Idea: A preconception and conception must precede every object of investigation, for how can anyone even investigate without some conception of the object of investigation? | |
From: Sextus Empiricus (Against the Professors (six books) [c.180], 8.331a) | |
A reaction: The Duhem-Quine thesis about the 'theory-ladenness of observation' is just a revival of some routine ancient scepticism. As well as a conceptual scheme to accommodate the observation, there must also be some motivation for the investigation. |
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) |
22746 | If we try to conceive of a line with no breadth, it ceases to exist, and so has no length [Sext.Empiricus] |
Full Idea: When we have gone so far as to deprive the length of its breadth altogether, we no longer conceive even the length, but along with the removal of the breadth the conception of the length is also removed. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.392) | |
A reaction: The only explanation of our retaining an understanding of a line even after we have removed its breadth is that we have abandoned experience and conceptualised the line - by idealising it. |
22741 | The incorporeal is not in the nature of body, and so could not emerge from it [Sext.Empiricus] |
Full Idea: The incorporeal will never come into existence from body because the nature of the incorporeal does not exist in body. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.225) | |
A reaction: So nothing high could be made of pebbles because pebbles are not high? His argument depends on incorporeality having an intrinsically incorporeal nature. Pebbles have some height which can be extended. |
6555 | We are also irrational, with a unique ability to believe in bizarre self-created fictions [Fogelin] |
Full Idea: We as human beings are also irrational animals, unique among animals in our capacity to place faith in bizarre fictions of our own construction. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Intro) | |
A reaction: This is glaringly true, and a very nice corrective to the talk of Greeks and others about man as the 'rational animal'. From a distance we might be described by Martians as the 'mad animal'. Is the irrational current too strong to swim against? |
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) |
22763 | We can only dream of a winged man if we have experienced men and some winged thing [Sext.Empiricus] |
Full Idea: He who in his sleep dreams of a winged man does not dream so without having seen some winged thing and a man. And in general it is impossible to find in conception anything which one does not possess as known by experience. | |
From: Sextus Empiricus (Against the Logicians (two books) [c.180], II.058) | |
A reaction: This precisely David Hume's empiricist account of the formation of concepts. Hume's example is a golden mountain, which he got from Aquinas. How do we dream of faces we have never encountered, or shapes we have never seen? |
6605 | Critics must be causally entangled with their subject matter [Fogelin] |
Full Idea: Critics must become causally entangled with their subject matter. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.6) | |
A reaction: This remark is built on Hume's views. You may have a strong view about a singer, but it may be hard to maintain when someone plays you six rival versions of the same piece. I agree entirely with the remark. It means there are aesthetic experts. |
6607 | The word 'beautiful', when deprived of context, is nearly contentless [Fogelin] |
Full Idea: Like the word 'good', the word 'beautiful', when deprived of contextual support, is nearly contentless. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.6) | |
A reaction: If I say with, for example, Oscar Wilde that beauty is the highest ideal in life, this doesn't strike me as contentless, but I still sympathise with Fogelin's notion that beauty is rooted in particulars. |
6604 | Saying 'It's all a matter to taste' ignores the properties of the object discussed [Fogelin] |
Full Idea: "It is all a matter of taste" may be an all-purpose stopper of discussions of aesthetic values, but it also completely severs the connection with the actual properties of the object under consideration. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.6) | |
A reaction: This remark grows out of his discussion of Hume. I like this remark, which ties in with Particularism in morality, and with the central role of experiments in science. The world forces beliefs on us. |
6586 | Cynics are committed to morality, but disappointed or disgusted by human failings [Fogelin] |
Full Idea: Cynics are usually unswerving in their commitment to a moral ideal, but disappointed or disgusted by humanity's failure to meet it. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.3) | |
A reaction: I felt quite suicidal the other day when I saw someone park diagonally across two parking spaces. They can't seem to grasp the elementary Kantian slogan 'What if everybody did that?' It's all hopeless. I wonder if I am becoming a bit of a Cynic? |
22754 | Saying the good is useful or choiceworth or happiness-creating is not the good, but a feature of it [Sext.Empiricus] |
Full Idea: Asserting that the good is 'the useful', or 'what is choiceworthy for its own sake', or 'that which contributes to happiness', does not teach us what good is but states its accidental property. | |
From: Sextus Empiricus (Against the Ethicists (one book) [c.180], II.35) | |
A reaction: This seems to be a pretty accurate statement of Moore's famous Open Question argument. I read it in an Aristotelian way - that that quest is always for the essential nature of the thing itself, not for its role or function or use. |
22755 | Like a warming fire, what is good by nature should be good for everyone [Sext.Empiricus] |
Full Idea: Just as fire which is warmth-giving by nature warms all men, and does not chill some of them, so what is good by nature ought to be good for all, and not good for some but not good for others. | |
From: Sextus Empiricus (Against the Ethicists (one book) [c.180], II.69) | |
A reaction: This is going to confine the naturally good to the basics of life, which we all share. Is a love of chess a natural good? It seems to capture an aspect of human nature, without appealing to everyone. Sextus says nothing is good for everyone. |
22756 | If a desire is itself desirable, then we shouldn't desire it, as achieving it destroys it [Sext.Empiricus] |
Full Idea: If the desire for wealth or health is desirable, we ought not to purse wealth or health, lest by acquiring them we cease to desire them any longer. | |
From: Sextus Empiricus (Against the Ethicists (one book) [c.180], II.81) | |
A reaction: He is investigating whether desires can be desirable, and if so which ones. Roots of this are in Plato's 'Gorgias' on drinking water. Similar to 'if compassion is the highest good then we need lots of suffering'. Desire must be a means, not an end. |
6032 | Right actions, once done, are those with a reasonable justification [Sext.Empiricus] |
Full Idea: Right action is whatever, once it has been done, has a reasonable justification. | |
From: Sextus Empiricus (Against the Professors (six books) [c.180], 7.158) | |
A reaction: Why does he add 'once it has been done'? Wouldn't a proposed action be right if it had a reasonable justification? This grows out of the classical and Stoic emphasis on reason in ethics, and leads towards Scanlon's Contractualism. |
6572 | Deterrence, prevention, rehabilitation and retribution can come into conflict in punishments [Fogelin] |
Full Idea: The purposes of punishment include deterrence, prevention, rehabilitation, and retribution, but they don't always sit well together. Deterrence is best served by making prisons miserable places, but this may run counter to rehabilitation. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.2) | |
A reaction: It seems to most educated people that retribution should be pushed far down the list if we are to be civilised (see Idea 1659), and yet personal revenge for a small act of aggression seems basic, normal and acceptable. We dream of rehabilitation. |
6573 | Retributivists say a crime can be 'paid for'; deterrentists still worry about potential victims [Fogelin] |
Full Idea: A strict retributivist is likely to say that once a crime is paid for, that's that; a deterrence theorist is likely to say that the protection of potential victims overrides the released convict's right to a free and fresh start. | |
From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.2) | |
A reaction: Interesting since the retributivist here has the more liberal attitude. Reformists will also have a dilemma when years in prison have failed to reform the convict. Virtue theorists like balance, and sensitively consider our relations with the criminals. |
1517 | The tektraktys (1+2+3+4=10) is the 'fount of ever-flowing nature' [Sext.Empiricus] |
Full Idea: The tektraktys (1+2+3+4=10) is the 'fount of ever-flowing nature', because nature is a harmony of three concords (4th,5th and octave), and these ratios (4:3, 3:2, and 2:1) are found in the tektraktys. | |
From: Sextus Empiricus (Against the Professors (six books) [c.180], 7.95) |
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) |
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. |
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) |
22747 | A man walking backwards on a forwards-moving ship is moving in a fixed place [Sext.Empiricus] |
Full Idea: If a ship moves forward and a man carries a rod backwards on it, then it is possible for an object to move without quitting its place. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], II.056) | |
A reaction: [summary of a verbose paragraph] The point is that you cannot define movement as change of place (contrary to Russell's proposal!). The concept of a place seems to be relative. Walking on a treadmill. |
20624 | Work degrades into heat, but not vice versa [Close] |
Full Idea: William Thomson, Lord Kelvin, declared (in 1865) the second law of thermodynamics: mechanical work inevitably tends to degrade into heat, but not vice versa. | |
From: Frank Close (Theories of Everything [2017], 3 'Perpetual') | |
A reaction: The basis of entropy, which makes time an essential part of physics. Might this be the single most important fact about the physical world? |
20623 | First Law: energy can change form, but is conserved overall [Close] |
Full Idea: The first law of thermodynamics : energy can be changed from one form to another, but is always conserved overall. | |
From: Frank Close (Theories of Everything [2017], 3 'Perpetual') | |
A reaction: So we have no idea what energy is, but we know it's conserved. (Daniel Bernoulli showed the greater the mean energy, the higher the temperature. James Joule showed the quantitative equivalence of heat and work p.26-7) |
20625 | Third Law: total order and minimum entropy only occurs at absolute zero [Close] |
Full Idea: The third law of thermodynamics says that a hypothetical state of total order and minimum entropy can be attained only at the absolute zero temperature, minus 273 degrees Celsius. | |
From: Frank Close (Theories of Everything [2017], 3 'Arrow') | |
A reaction: If temperature is energetic movement of atoms (or whatever), then obviously zero movement is the coldest it can get. So is absolute zero an energy state, or an absence of energy? I have no idea what 'total order' means. |
20622 | All motions are relative and ambiguous, but acceleration is the same in all inertial frames [Close] |
Full Idea: There is no absolute state of rest; only relative motions are unambiguous. Contrast this with acceleration, however, which has the same magnitude in all inertial frames. | |
From: Frank Close (Theories of Everything [2017], 3 'Newton's') | |
A reaction: It seems important to remember this, before we start trumpeting about the whole of physics being relative. ....But see Idea 20634! |
20628 | The electric and magnetic are tightly linked, and viewed according to your own motion [Close] |
Full Idea: Electric and magnetic phenomena are profoundly intertwined; what you interpret as electric or magnetic thus depends on your own motion. | |
From: Frank Close (Theories of Everything [2017], 3 'Light!') | |
A reaction: This sounds like an earlier version of special relativity. |
20635 | The general relativity equations relate curvature in space-time to density of energy-momentum [Close] |
Full Idea: The essence of general relativity relates 'curvature in space-time' on one side of the equation to the 'density of momentum and energy' on the other. ...In full, Einstein required ten equations of this type. | |
From: Frank Close (Theories of Everything [2017], 5 'Gravity') | |
A reaction: Momentum involves mass, and energy is equivalent to mass (e=mc^2). |
20627 | Electric fields have four basic laws (two by Gauss, one by Ampère, one by Faraday) [Close] |
Full Idea: Four basic laws of electric and magnetic fields: Gauss's Law (about the flux produced by a field), Gauss's law of magnets (there can be no monopoles), Ampère's Law (fields on surfaces), and Farday's Law (accelerated magnets produce fields). | |
From: Frank Close (Theories of Everything [2017], 3 'Light!') | |
A reaction: [Highly compressed, for an overview. Close explains them] |
20630 | Light isn't just emitted in quanta called photons - light is photons [Close] |
Full Idea: Planck had assumed that light is emitted in quanta called photons. Einstein went further - light is photons. | |
From: Frank Close (Theories of Everything [2017], 3 'Light!') | |
A reaction: The point is that light travels as entities which are photons, rather than the emissions being quantized packets of some other stuff. |
20637 | In general relativity the energy and momentum of photons subjects them to gravity [Close] |
Full Idea: In Einstein's general theory, gravity acts also on energy and momentum, not simply on mass. For example, massless photons of light feel the gravitational attraction of the Sun and can be deflected. | |
From: Frank Close (Theories of Everything [2017], 5 'Planck') | |
A reaction: Ah, a puzzle solved. How come massless photons are bent by gravity? |
20629 | Electro-magnetic waves travel at light speed - so light is electromagnetism! [Close] |
Full Idea: Faradays' measurements predicted the speed of electro-magnetic waves, which happened to be the speed of light, so Maxwell made an inspired leap: light is an electromagnetic wave! | |
From: Frank Close (Theories of Everything [2017], 3 'Light!') | |
A reaction: Put that way, it doesn't sound like an 'inspired' leap, because travelling at exactly the same speed seems a pretty good indication that they are the same sort of thing. (But I'm not denying that Maxwell was a special guy!) |
20632 | In QED, electro-magnetism exists in quantum states, emitting and absorbing electrons [Close] |
Full Idea: Dirac created quantum electrodynamics (QED): the universal electro-magnetic field can exist in discreet states of energy (with photons appearing and disappearing by energy excitations. This combined classical ideas, quantum theory and special relativity. | |
From: Frank Close (Theories of Everything [2017], 3 'Light!') | |
A reaction: Close says this is the theory of everything in atomic structure, but not in nuclei (which needs QCD and QFD). So if there are lots of other 'fields' (e.g. gravitational, weak, strong, Higgs), how do they all fit together? Do they talk to one another? |
20642 | Photon exchange drives the electro-magnetic force [Close] |
Full Idea: The exchange of photons drives the electro-magnetic force. | |
From: Frank Close (Theories of Everything [2017], 6 'Superstrings') | |
A reaction: So light, which we just think of as what is visible, is a mere side-effect of the engine room of nature - the core mechanism of the whole electro-magnetic field. |
20639 | Quantum fields contain continual rapid creation and disappearance [Close] |
Full Idea: Quantum field theory implies that the vacuum of space is filled with particles and antiparticles which bubble in and out of existence on faster and faster timescales over shorter and shorter distances. | |
From: Frank Close (Theories of Everything [2017], 6 'Intro') | |
A reaction: Ponder this sentence until you head aches. Existence, but not as we know it, Jim. Close says calculations in QED about the electron confirm this. |
20631 | Dirac showed how electrons conform to special relativity [Close] |
Full Idea: In 1928 Paul Dirac discovered the quantum equation that describes the electron and conforms to the requirements special relativity theory. | |
From: Frank Close (Theories of Everything [2017], 3 'Light!') | |
A reaction: This sounds like a major step in the unification of physics. Quantum theory and General relativity remain irreconcilable. |
20641 | Electrons get their mass by interaction with the Higgs field [Close] |
Full Idea: The electron gets its mass by interaction with the ubiquitous Higgs field. | |
From: Frank Close (Theories of Everything [2017], 6 'Hierarchy') | |
A reaction: I thought I understood mass until I read this. Is it just wrong to say the mass of a table is the 'amount of stuff' in it? |
20626 | Modern theories of matter are grounded in heat, work and energy [Close] |
Full Idea: The link between temperature, heat, work and energy is at the root of our historical ability to construct theories of matter, such as Newton's dynamics, while ignoring, and indeed being ignorant of - atomic dimensions. | |
From: Frank Close (Theories of Everything [2017], 3 'Arrow') | |
A reaction: That is, presumably, that even when you fill in the atoms, and the standard model of physics, these aspects of matter do the main explaiining (of the behaviour, rather than of the structure). |
20633 | The Higgs field is an electroweak plasma - but we don't know what stuff it consists of [Close] |
Full Idea: In 2012 it was confirmed that we are immersed in an electroweak plasma - the Higgs field. We curently have no knowledge of what this stuff might consist of. | |
From: Frank Close (Theories of Everything [2017], 4 'Higgs') | |
A reaction: The second sentence has my full attention. So we don't understand a field properly until we understand the 'stuff' it is made of? So what are all the familiar fields made of? Tell me more! |
20640 | Space-time is indeterminate foam over short distances [Close] |
Full Idea: At very short distances, space-time itself becomes some indeterminate foam. | |
From: Frank Close (Theories of Everything [2017], 6 'Intro') | |
A reaction: [see Close for a bit more detail of this weird idea] |
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) |
22749 | Time doesn't end with the Universe, because tensed statements about destruction remain true [Sext.Empiricus] |
Full Idea: It is absurd to say that when the Universe is destroyed time does not exist; for the statement that it was destroyed once and that it is being destroyed are indicative of times. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], II.188) | |
A reaction: Intriguing. He takes it that a proposition can be true even though nothing exists. This is not merely an affirmation of the tensed A-series view of time, but he even offers tenses as evidence that the A-series is correct. That time could cease was a view. |
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) |
22750 | Time is divisible, into past, present and future [Sext.Empiricus] |
Full Idea: Time cannot be indivisible, since it is divided into past, present and future. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], II.193) | |
A reaction: Does the fact that you can name the parts of something prove that it is divisible? Do electrons have left and right-hand sides? |
22742 | Socrates either dies when he exists (before his death) or when he doesn't (after his death) [Sext.Empiricus] |
Full Idea: Socrates either dies when existing, or when not existing. …He does not die when he exists, for he is alive, and he does not die when he has died, for then he will be dying twice, which is absurd. So then, Socrates does not die. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.269) | |
A reaction: A nice dramatisation of a major dilemma. The present moment is just the boundary between the past and the future, and so has no magnitude, and hence nothing can occur during the present. Perhaps my favourite philosophical dilemma. |
22751 | If the present is just the limit of the past or the future, it can't exist because they don't exist [Sext.Empiricus] |
Full Idea: If the present is the limit of the past, and the limit of the past has passed away together with that of which it is the limit, the present no longer exists. And if the present begins the future, which doesn't exist, the present does not yet exist. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], II.201) | |
A reaction: If I mark a line on the ground where the wall will begin, the limit seems prior to the object. The gun starts the race, but is not part of it. That said, I cannot think of any more mysterious entity than the present moment. It isn't a line or a bang. |
22730 | All men agree that God is blessed, imperishable, happy and good [Sext.Empiricus] |
Full Idea: All men have one common preconception about God, according to which he is a blessed creature and imperishable and perfect in happiness and receptive of nothing evil. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.033) | |
A reaction: He observes this after he has pointed the enormous variety of religious beliefs. He offers this unanimity as a reason to believe that it is true. |
22739 | God must suffer to understand suffering [Sext.Empiricus] |
Full Idea: God cannot have a notion of suffering if he has not experience it. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.163) | |
A reaction: Christians like to portray God as suffering because of his son's horrible death. We can imagine experiences we have never had, and presumably God is better at that than we are. |
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) |
22738 | The Divine must lack the virtues of continence and fortitude, because they are not needed [Sext.Empiricus] |
Full Idea: If the Divine is all-virtuous, it possesses all the virtues. But it does not possess the virtues of continence and fortitude unless there are certain things which are hard for God to abstain from and hard to endure. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.151) | |
A reaction: Courage would also be unnecessary, we assume. Good people are not tempted to steal, and hence do not need to resist it. It is a mistake to attribute human virtues to the Divine. Humans lack the virtues of a good frog. |
22734 | God is defended by agreement, order, absurdity of denying God, and refutations [Sext.Empiricus] |
Full Idea: Arguments for God have four modes: from universal agreement, from the orderly arrangement of the universe, from the absurd consequences of denying God, and from undermining the opposing arguments. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.060) | |
A reaction: [compressed] The loss of status of the argument from universal agreement has had a huge influence. We now realise that a very wide consensus is no guarantee of truth in anything. |
22736 | God's sensations imply change, and hence perishing, which is absurd, so there is no such God [Sext.Empiricus] |
Full Idea: If God has sensation he is altered, …so he is receptive of change, including change for the worse. If so, he is also perishable, but that is absurd; therefore it is absurd also to claim that God exists. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.146) | |
A reaction: [compressed] It is certainly paradoxical to think that God is eternal and unchanging, but also capable of perception and thought, which necessitate change. Some theological ingenuity is needed to explain this. |
22740 | God without virtue is absurd, but God's virtues will be better than God [Sext.Empiricus] |
Full Idea: If the Divine exists it either has or has not virtue. If it has not it is base and unhappy, which is absurd. But if it has it, there will exist something which is better than God, just as a virtue of a horse is better than the horse itself. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.176) | |
A reaction: It is obviously better to think of a virtue as some mode of a thing, rather than as a separate attachment. This is an ontological argument, because it is inferred from the concept of God. |
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) |
22735 | The original substance lacked motion or shape, and was given these by a cause [Sext.Empiricus] |
Full Idea: They say that the substance of existing things being of itself motionless and shapeless must be put in motion and shape by some cause. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.075) | |
A reaction: Interestingly, Sextus doesn't seem to think that the existence of the original substance also needs a cause. This substance sounds like a relative of Aristotle's Prime Matter. The source of motion isn't really a 'design' argument. |
22732 | The perfections of God were extrapolations from mankind [Sext.Empiricus] |
Full Idea: It is said that …the idea that God is eternal and imperishable and perfect in happiness was introduced by way of transference from mankind. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.045) | |
A reaction: This view is found in Hume, and in Feuerbach. I presume 'transference' means extrapolation and idealisation. If God exists, we may have no option but to think of God anthropomorphically. |
22728 | Gods were invented as watchers of people's secret actions [Sext.Empiricus] |
Full Idea: It is asserted that those who first led mankind …invented gods as watchers of all the sinful and righteous acts of men, so that none should dare to do wrong even in secret. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.016) | |
A reaction: Sextus is a sceptic about everything, so this scepticism about the gods is nothing special. I'm not sure if this is why the gods were invented, but it seems to be the main role assigned to God by the Christian church, as the basis of religious morality. |
22737 | An incorporeal God could do nothing, and a bodily god would perish, so there is no God [Sext.Empiricus] |
Full Idea: The Divine is not incorporeal, since that is inanimate and insensitive and incapable of any action; nor is it a body, since that is subject to change and perishable; so the Divine does not exist. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.151) | |
A reaction: I find this quite persuasive. An incorporeal God has to be ascribed magical powers in order to interact with what is corporeal. A corporeal God is subject to entropy and all the depredations of the physical world. |
22731 | It is mad to think that what is useful to us, like lakes and rivers, are gods [Sext.Empiricus] |
Full Idea: To suppose that lakes and rivers, and whatsoever else is of a nature to be useful to us, are gods surpasses the height of lunacy. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.040) | |
A reaction: He also points out the what is useful to us decays and changes. Sextus lived in a time when monotheism was becoming dominant. |
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) |