35 ideas
| 8952 | We reach 'reflective equilibrium' when intuitions and theory completely align [Fisher] |
| Full Idea: A state of 'reflective equilibrium' is when our theory and our intuitions become completely aligned | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 12.IV) | |
| A reaction: [Rawls made this concept famous] This is a helpful concept in trying to spell out the ideal which is the dream of believers in 'pure reason' - that there is a goal in which everything comes right. The problem is when people have different intuitions! |
| 501 | Reason is a more powerful persuader than gold [Democritus (attr)] |
| Full Idea: In power of persuasion, reasoning is far stronger than gold. | |
| From: Democritus (attrib) (reports [c.250 BCE], B051), quoted by John Stobaeus - Anthology 2.04.12 |
| 7726 | Aristotelian logic dealt with inferences about concepts, and there were also proposition inferences [Weiner] |
| Full Idea: Till the nineteenth century, it was a common view that Aristotelian logic could evaluate inferences whose validity was based on relations between concepts, while propositional logic could evaluate inferences based on relations between propositions. | |
| From: Joan Weiner (Frege [1999], Ch.3) | |
| A reaction: Venn diagrams relate closely to Aristotelian syllogisms, as each concept is represented by a circle, and shows relations between sets. Arrows seem needed to represent how to go from one proposition to another. Is one static, the other dynamic? |
| 8943 | Three-valued logic says excluded middle and non-contradition are not tautologies [Fisher] |
| Full Idea: In three-valued logic (L3), neither the law of excluded middle (p or not-p), nor the law of non-contradiction (not(p and not-p)) will be tautologies. If p has the value 'indeterminate' then so will not-p. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 07.I) | |
| A reaction: I quite accept that the world is full of indeterminate propositions, and that excluded middle and non-contradiction can sometimes be uncertain, but I am reluctant to accept that what is being offered here should be called 'logic'. |
| 8945 | Fuzzy logic has many truth values, ranging in fractions from 0 to 1 [Fisher] |
| Full Idea: In fuzzy logic objects have properties to a greater or lesser degree, and truth values are given as fractions or decimals, ranging from 0 to 1. Not-p is defined as 1-p, and other formula are defined in terms of maxima and minima for sets. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 07.II) | |
| A reaction: The question seems to be whether this is actually logic, or a recasting of probability theory. Susan Haack attacks it. If logic is the study of how truth is preserved as we move between propositions, then 0 and 1 need a special status. |
| 8951 | Classical logic is: excluded middle, non-contradiction, contradictions imply all, disjunctive syllogism [Fisher] |
| Full Idea: For simplicity, we can say that 'classical logic' amounts to the truth of four sentences: 1) either p or not-p; 2) it is not the case that both p and not-p; 3) from p and not-p, infer q; 4) from p or q and not-p, infer q. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 12.I) | |
| A reaction: [She says there are many ways of specifying classical logic] Intuition suggests that 2 and 4 are rather hard to dispute, while 1 is ignoring some grey areas, and 3 is totally ridiculous. There is, of course, plenty of support for 3! |
| 8950 | Logic formalizes how we should reason, but it shouldn't determine whether we are realists [Fisher] |
| Full Idea: Even if one is inclined to be a realist about everything, it is hard to see why our logic should be the determiner. Logic is supposed to formalize how we ought to reason, but whether or not we should be realists is a matter of philosophy, not logic. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 09.I) | |
| A reaction: Nice to hear a logician saying this. I do not see why talk in terms of an object is a commitment to its existence. We can discuss the philosopher's stone, or Arthur's sword, or the Loch Ness monster, or gravitinos, with degrees of commitment. |
| 8946 | We could make our intuitions about heaps precise with a million-valued logic [Fisher] |
| Full Idea: We could construct a 1,000,000-valued logic that would allow our intuitions concerning a heap to vary exactly with the amount of sand in the heap. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008]) | |
| A reaction: Presumably only an infinite number of grains of sand would then produce a true heap, and even one grain would count as a bit of a heap, which must both be wrong, so I can't see this helping much. |
| 8944 | Vagueness can involve components (like baldness), or not (like boredom) [Fisher] |
| Full Idea: Vague terms come in at least two different kinds: those whose constituent parts come in discrete packets (bald, rich, red) and those that don't (beauty, boredom, niceness). | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 07.II) | |
| A reaction: The first group seem to be features of the external world, and the second all occur in the mind. Baldness may be vague, but presumably hairs are (on the whole) not. Nature doesn't care whether someone is actually 'bald' or not. |
| 8941 | We can't explain 'possibility' in terms of 'possible' worlds [Fisher] |
| Full Idea: Explaining 'it is possible that p' by saying p is true in at least one possible world doesn't get me very far. If I don't understand what possibility is, then appealing to possible worlds is not going to do me much good. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 06.III) | |
| A reaction: This seems so blatant that I assume friends of possible worlds will have addressed the problem. Note that you will also need to understand 'possible' to define necessity as 'true in all possible worlds'. Necessarily-p is not-possibly-not-p. |
| 8947 | If all truths are implied by a falsehood, then not-p might imply both q and not-q [Fisher] |
| Full Idea: If all truths are implied by a falsehood, then 'if there are no trees in the park then there is no shade' and 'if there are no trees in the park there is plenty of shade' both come out as true. Intuitively, though, the second one is false. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 08.I) | |
| A reaction: The rule that a falsehood implies all truths must be the weakest idea in classical logic, if it actually implies a contradiction. This means we must take an interest in relevance logics. |
| 8949 | In relevance logic, conditionals help information to flow from antecedent to consequent [Fisher] |
| Full Idea: A good account of relevance logic suggests that a conditional will be true when the flow of information is such that a conditional is the device that helps information to flow from the antecedent to the consequent. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 08.III) | |
| A reaction: Hm. 'If you are going out, you'll need an umbrella'. This passes on information about 'out', but also brings in new information. 'If you are going out, I'm leaving you'. What flows is an interpretation of the antecedent. Tricky. |
| 514 | Beauty is merely animal without intelligence [Democritus (attr)] |
| Full Idea: Physical beauty is merely animal unless intelligence be present. | |
| From: Democritus (attrib) (reports [c.250 BCE], B105) |
| 525 | Behave well when alone, and feel shame in you own eyes [Democritus (attr)] |
| Full Idea: Do not say or do what is base, even when you are alone. Learn to feel shame in your own eyes much more than before others. | |
| From: Democritus (attrib) (reports [c.250 BCE], B244), quoted by John Stobaeus - Anthology 3.31.7 | |
| A reaction: I like this. How you think and behave when unobserved is the true test of who you are. Feeling shame at a very private failing is an interesting phenomenon. |
| 502 | Good breeding in men means having a good character [Democritus (attr)] |
| Full Idea: Good breeding in cattle depends on physical health, but in men on a well-formed character. | |
| From: Democritus (attrib) (reports [c.250 BCE], B057), quoted by John Stobaeus - Anthology 4.29.18 | |
| A reaction: In our ultra-democratic age (supposedly) it is heresy to talk about good breeding, or some people being superior to others. But surely people should aim to improve their characters? |
| 507 | Virtuous love consists of decorous desire for the beautiful [Democritus (attr)] |
| Full Idea: Virtuous love consists of decorous desire for the beautiful. | |
| From: Democritus (attrib) (reports [c.250 BCE], B073), quoted by John Stobaeus - Anthology 3.5.23 | |
| A reaction: Is it possible to love something without seeing it as beautiful? A badly crippled dog, for example. If not, that seems to reveal something about beauty. |
| 521 | We should only choose pleasures which are concerned with the beautiful [Democritus (attr)] |
| Full Idea: One should choose not every pleasure, but only that concerned with the beautiful. | |
| From: Democritus (attrib) (reports [c.250 BCE], B207), quoted by John Stobaeus - Anthology 3.05.22 | |
| A reaction: The pleasures we should prefer are those which involve the whole person, rather than the mere stimulation of one sense. Sez me. |
| 505 | Good and true are the same for everyone, but pleasures differ [Democritus (attr)] |
| Full Idea: For all men, good and true are the same; but pleasant differs for different men. | |
| From: Democritus (attrib) (reports [c.250 BCE], B069) | |
| A reaction: Truth is not 'for' anyone, but there's good-in-itself, and good-for-me. Are there some pleasures we should all enjoy (such as watching our children flourish)? |
| 508 | Only accept beneficial pleasures [Democritus (attr)] |
| Full Idea: Accept no pleasure unless it is beneficial. | |
| From: Democritus (attrib) (reports [c.250 BCE], B074) | |
| A reaction: Maybe all pleasures bestow some benefit - even if they are linked to harm. I struggle to see what is wrong with a harmless and non-beneficial pleasure, and I doubt if anyone could explain it to me. |
| 520 | The great pleasures come from the contemplation of noble works [Democritus (attr)] |
| Full Idea: The great pleasures come from the contemplation of noble works. | |
| From: Democritus (attrib) (reports [c.250 BCE], B194), quoted by John Stobaeus - Anthology 3.03.46 | |
| A reaction: Only, of course, for those able to perceive the nobility. In what does the 'nobility' consist, other than in the morally acceptable pleasure? Hard to explain 'noble'. Just 'wow!'? |
| 522 | Moderation brings more pleasures, and so increases pleasure [Democritus (attr)] |
| Full Idea: Moderation multiplies pleasures, and increases pleasure. | |
| From: Democritus (attrib) (reports [c.250 BCE], B211), quoted by John Stobaeus - Anthology 3.05.27 | |
| A reaction: So moderation is a sneaky trick to avoid moderation? I presume the most intense pleasures are mostly unfamiliar, and so add novelty to the mix. Apart from eating chocolate, of course. |
| 506 | Immoderate desire is the mark of a child, not an adult [Democritus (attr)] |
| Full Idea: Immoderate desire is the mark of a child, not a man. | |
| From: Democritus (attrib) (reports [c.250 BCE], B070) | |
| A reaction: Not factually correct, since the world is full of adults who have immoderate desires (notably for money). However, there are plenty of grown ups who don't seem very adult. |
| 523 | It is as brave to master pleasure as to overcome the enemy [Democritus (attr)] |
| Full Idea: The brave man is not only he who overcomes the enemy, but he who is stronger than pleasures. Some men are masters of cities, but are enslaved by women. | |
| From: Democritus (attrib) (reports [c.250 BCE], B214), quoted by John Stobaeus - Anthology 3.07.25 | |
| A reaction: I'm not sure if 'bravery' is the relevant virtue here.Sounds like self-control or temperance. I suspect that mastering a city is quite pleasurable, if that's your thing. |
| 503 | Virtue doesn't just avoid evil, but also doesn't desire it [Democritus (attr)] |
| Full Idea: Virtue consists, not in avoiding wrong-doing, but in having no wish thereto. | |
| From: Democritus (attrib) (reports [c.250 BCE], B062), quoted by John Stobaeus - Anthology 3.17.37 |
| 497 | Be virtuous from duty, not from fear [Democritus (attr)] |
| Full Idea: Refrain from crimes not through fear but through duty [deon]. | |
| From: Democritus (attrib) (reports [c.250 BCE], B041), quoted by John Stobaeus - Anthology 3.01.95 | |
| A reaction: [not sure about the translation here] |
| 518 | A bad life is just a drawn-out death [Democritus (attr)] |
| Full Idea: To live badly is not just to live badly, but to spend a long time dying. | |
| From: Democritus (attrib) (reports [c.250 BCE], B160), quoted by (who?) - where? |
| 499 | Repentance of shameful deeds is salvation [Democritus (attr)] |
| Full Idea: Repentance for shameful deeds is salvation in life. | |
| From: Democritus (attrib) (reports [c.250 BCE], B043) |
| 524 | Virtue comes more from practice than from nature [Democritus (attr)] |
| Full Idea: More men become good through practice than by nature. | |
| From: Democritus (attrib) (reports [c.250 BCE], B242), quoted by John Stobaeus - Anthology 3.29.66 |
| 519 | One must avoid even speaking of evil deeds [Democritus (attr)] |
| Full Idea: One must avoid even speaking of evil deeds. | |
| From: Democritus (attrib) (reports [c.250 BCE], B190), quoted by John Stobaeus - Anthology 3.01.91 |
| 500 | The wrongdoer is more unfortunate than the person wronged [Democritus (attr)] |
| Full Idea: The wrongdoer is more unfortunate than the man wronged. | |
| From: Democritus (attrib) (reports [c.250 BCE], B045) |
| 1539 | The endless desire for money is a crueller slavery than poverty [Democritus (attr)] |
| Full Idea: Unless a point of satiety is reached, the desire for money is far more cruel than the utmost poverty, because the greater the desire, the greater the need | |
| From: Democritus (attrib) (reports [c.250 BCE], B219), quoted by John Stobaeus - Anthology 3.10.43 |
| 526 | Small appetite makes poverty equal to wealth [Democritus (attr)] |
| Full Idea: Small appetite makes poverty equivalent to wealth. | |
| From: Democritus (attrib) (reports [c.250 BCE], B284), quoted by John Stobaeus - Anthology 4.33.24 |
| 511 | It is better to have one intelligent friend than many unintelligent [Democritus (attr)] |
| Full Idea: The friendship of one intelligent man is better than that of all the unintelligent. | |
| From: Democritus (attrib) (reports [c.250 BCE], B098) |
| 498 | It is a great thing, when one is in adversity, to think of duty [Democritus (attr)] |
| Full Idea: It is a great thing, when one is in adversity, to think of duty. | |
| From: Democritus (attrib) (reports [c.250 BCE], B042), quoted by John Stobaeus - Anthology 4.44.68 | |
| A reaction: Something wrong with the translation here, if there is no Greek word for 'duty'. |
| 1541 | It is better to be poor in a democracy than be rich without freedom [Democritus (attr)] |
| Full Idea: Poverty in a democracy is as preferable to what is called prosperity under autocracy as freedom is to slavery. | |
| From: Democritus (attrib) (reports [c.250 BCE], B251), quoted by John Stobaeus - Anthology 3.40.42 |