67 ideas
| 15447 | We shouldn't always follow where the argument leads! [Lewis on Plato] |
| Full Idea: There comes a time not to go on following where the argument leads! | |
| From: comment on Plato (The Laws [c.348 BCE], 667b) by David Lewis - Against Structural Universals 'Variant' | |
| A reaction: Lewis is a fine one to talk, since he follows argument that take him past innumerable incredulous stares of onlookers. |
| 243 | It is foolish to quarrel with the mind's own reasoning processes [Plato] |
| Full Idea: When the soul quarrels with knowledge or opinion or reason, its natural ruling principles, you have there what I call 'folly'. | |
| From: Plato (The Laws [c.348 BCE], 689b) |
| 241 | We ought to follow where the argument leads us [Plato] |
| Full Idea: We ought to follow where the argument leads us. | |
| From: Plato (The Laws [c.348 BCE], 667a) |
| 21264 | Mortals are incapable of being fully rational [Plato] |
| Full Idea: We mustn't assume that mortal eyes will ever be able to look upon reason and get to know it adequately. | |
| From: Plato (The Laws [c.348 BCE], 897d) | |
| A reaction: This is in the context of the rational control of the whole Cosmos. I presume Plato would be flabbergasted by the findings of recent physics and cosmology. Did Kant believe that he was being completely rational about ethics? |
| 251 | Truth has the supreme value, for both gods and men [Plato] |
| Full Idea: Truth heads the list of all things good, for gods and men alike. | |
| From: Plato (The Laws [c.348 BCE], 730c) |
| 10676 | The Axiom of Choice is a non-logical principle of set-theory [Hossack] |
| Full Idea: The Axiom of Choice seems better treated as a non-logical principle of set-theory. | |
| From: Keith Hossack (Plurals and Complexes [2000], 4 n8) | |
| A reaction: This reinforces the idea that set theory is not part of logic (and so pure logicism had better not depend on set theory). |
| 10686 | The Axiom of Choice guarantees a one-one correspondence from sets to ordinals [Hossack] |
| Full Idea: We cannot explicitly define one-one correspondence from the sets to the ordinals (because there is no explicit well-ordering of R). Nevertheless, the Axiom of Choice guarantees that a one-one correspondence does exist, even if we cannot define it. | |
| From: Keith Hossack (Plurals and Complexes [2000], 10) |
| 10687 | Maybe we reduce sets to ordinals, rather than the other way round [Hossack] |
| Full Idea: We might reduce sets to ordinal numbers, thereby reversing the standard set-theoretical reduction of ordinals to sets. | |
| From: Keith Hossack (Plurals and Complexes [2000], 10) | |
| A reaction: He has demonstrated that there are as many ordinals as there are sets. |
| 10677 | Extensional mereology needs two definitions and two axioms [Hossack] |
| Full Idea: Extensional mereology defs: 'distinct' things have no parts in common; a 'fusion' has some things all of which are parts, with no further parts. Axioms: (transitivity) a part of a part is part of the whole; (sums) any things have a unique fusion. | |
| From: Keith Hossack (Plurals and Complexes [2000], 5) |
| 10671 | Plural definite descriptions pick out the largest class of things that fit the description [Hossack] |
| Full Idea: If we extend the power of language with plural definite descriptions, these would pick out the largest class of things that fit the description. | |
| From: Keith Hossack (Plurals and Complexes [2000], 3) |
| 10666 | Plural reference will refer to complex facts without postulating complex things [Hossack] |
| Full Idea: It may be that plural reference gives atomism the resources to state complex facts without needing to refer to complex things. | |
| From: Keith Hossack (Plurals and Complexes [2000], 1) | |
| A reaction: This seems the most interesting metaphysical implication of the possibility of plural quantification. |
| 10669 | Plural reference is just an abbreviation when properties are distributive, but not otherwise [Hossack] |
| Full Idea: If all properties are distributive, plural reference is just a handy abbreviation to avoid repetition (as in 'A and B are hungry', to avoid 'A is hungry and B is hungry'), but not all properties are distributive (as in 'some people surround a table'). | |
| From: Keith Hossack (Plurals and Complexes [2000], 2) | |
| A reaction: The characteristic examples to support plural quantification involve collective activity and relations, which might be weeded out of our basic ontology, thus leaving singular quantification as sufficient. |
| 10675 | A plural comprehension principle says there are some things one of which meets some condition [Hossack] |
| Full Idea: Singular comprehension principles have a bad reputation, but the plural comprehension principle says that given a condition on individuals, there are some things such that something is one of them iff it meets the condition. | |
| From: Keith Hossack (Plurals and Complexes [2000], 4) |
| 10673 | Plural language can discuss without inconsistency things that are not members of themselves [Hossack] |
| Full Idea: In a plural language we can discuss without fear of inconsistency the things that are not members of themselves. | |
| From: Keith Hossack (Plurals and Complexes [2000], 4) | |
| A reaction: [see Hossack for details] |
| 10680 | The theory of the transfinite needs the ordinal numbers [Hossack] |
| Full Idea: The theory of the transfinite needs the ordinal numbers. | |
| From: Keith Hossack (Plurals and Complexes [2000], 8) |
| 10684 | I take the real numbers to be just lengths [Hossack] |
| Full Idea: I take the real numbers to be just lengths. | |
| From: Keith Hossack (Plurals and Complexes [2000], 9) | |
| A reaction: I love it. Real numbers are beginning to get on my nerves. They turn up to the party with no invitation and improperly dressed, and then refuse to give their names when challenged. |
| 10674 | A plural language gives a single comprehensive induction axiom for arithmetic [Hossack] |
| Full Idea: A language with plurals is better for arithmetic. Instead of a first-order fragment expressible by an induction schema, we have the complete truth with a plural induction axiom, beginning 'If there are some numbers...'. | |
| From: Keith Hossack (Plurals and Complexes [2000], 4) |
| 10681 | In arithmetic singularists need sets as the instantiator of numeric properties [Hossack] |
| Full Idea: In arithmetic singularists need sets as the instantiator of numeric properties. | |
| From: Keith Hossack (Plurals and Complexes [2000], 8) |
| 10685 | Set theory is the science of infinity [Hossack] |
| Full Idea: Set theory is the science of infinity. | |
| From: Keith Hossack (Plurals and Complexes [2000], 10) |
| 10668 | We are committed to a 'group' of children, if they are sitting in a circle [Hossack] |
| Full Idea: By Quine's test of ontological commitment, if some children are sitting in a circle, no individual child can sit in a circle, so a singular paraphrase will have us committed to a 'group' of children. | |
| From: Keith Hossack (Plurals and Complexes [2000], 2) | |
| A reaction: Nice of why Quine is committed to the existence of sets. Hossack offers plural quantification as a way of avoiding commitment to sets. But is 'sitting in a circle' a real property (in the Shoemaker sense)? I can sit in a circle without realising it. |
| 10664 | Complex particulars are either masses, or composites, or sets [Hossack] |
| Full Idea: Complex particulars are of at least three types: masses (which sum, of which we do not ask 'how many?' but 'how much?'); composite individuals (how many?, and summing usually fails); and sets (only divisible one way, unlike composites). | |
| From: Keith Hossack (Plurals and Complexes [2000], 1) | |
| A reaction: A composite pile of grains of sand gradually becomes a mass, and drops of water become 'water everywhere'. A set of people divides into individual humans, but redescribe the elements as the union of males and females? |
| 10678 | The relation of composition is indispensable to the part-whole relation for individuals [Hossack] |
| Full Idea: The relation of composition seems to be indispensable in a correct account of the part-whole relation for individuals. | |
| From: Keith Hossack (Plurals and Complexes [2000], 7) | |
| A reaction: This is the culmination of a critical discussion of mereology and ontological atomism. At first blush it doesn't look as if 'composition' has much chance of being a precise notion, and it will be plagued with vagueness. |
| 10665 | Leibniz's Law argues against atomism - water is wet, unlike water molecules [Hossack] |
| Full Idea: We can employ Leibniz's Law against mereological atomism. Water is wet, but no water molecule is wet. The set of infinite numbers is infinite, but no finite number is infinite. ..But with plural reference the atomist can resist this argument. | |
| From: Keith Hossack (Plurals and Complexes [2000], 1) | |
| A reaction: The idea of plural reference is to state plural facts without referring to complex things, which is interesting. The general idea is that we have atomism, and then all the relations, unities, identities etc. are in the facts, not in the things. I like it. |
| 10682 | The fusion of five rectangles can decompose into more than five parts that are rectangles [Hossack] |
| Full Idea: The fusion of five rectangles may have a decomposition into more than five parts that are rectangles. | |
| From: Keith Hossack (Plurals and Complexes [2000], 8) |
| 21259 | To grasp a thing we need its name, its definition, and what it really is [Plato] |
| Full Idea: There are three elements in any given thing: the first is what the object actually is, the second is the definition of this, and the third is the name. | |
| From: Plato (The Laws [c.348 BCE], 895d) | |
| A reaction: I take the importance of this to be its distinction between what it is, and the definition of what it is. Aristotle maintains this distinction, but some modern Aristotelians seem to get the confused. Plato worried a lot more about names than we do. |
| 19440 | How do you know you have conceived a thing deeply enough to assess its possibility? [Vaidya] |
| Full Idea: The main issue with learning possibility from conceivability concerns how we can be confident that we have conceived things to the relevant level of depth required for the scenario to actually be a presentation or manifestation of a genuine possibility. | |
| From: Anand Vaidya (The Epistemology of Modality [2015], 1.2.2) | |
| A reaction: [He cites Van Inwagen 1998 for this idea] The point is that ignorant imagination can conceive of all sorts of absurd things which are seen to be impossible when enough information is available. We can hardly demand a criterion for this. |
| 21260 | Soul is what is defined by 'self-generating motion' [Plato] |
| Full Idea: The entity which we call 'soul' is precisely that which is defined by the expression 'self-generating motion'. | |
| From: Plato (The Laws [c.348 BCE], 896a) | |
| A reaction: We may suspect that he defines soul in this way for a particular context, aimed at proving the existence of a First Mover. He must think there is more to soul than the generation of movement. |
| 276 | My individuality is my soul, which carries my body around [Plato] |
| Full Idea: While I am alive I have nothing to thank for my individuality except my soul, whereas my body is just the likeness that I carry around with me. | |
| From: Plato (The Laws [c.348 BCE], 959a) |
| 10663 | A thought can refer to many things, but only predicate a universal and affirm a state of affairs [Hossack] |
| Full Idea: A thought can refer to a particular or a universal or a state of affairs, but it can predicate only a universal and it can affirm only a state of affairs. | |
| From: Keith Hossack (Plurals and Complexes [2000], 1) | |
| A reaction: Hossack is summarising Armstrong's view, which he is accepting. To me, 'thought' must allow for animals, unlike language. I think Hossack's picture is much too clear-cut. Do animals grasp universals? Doubtful. Can they predicate? Yes. |
| 249 | People who value beauty above virtue insult the soul by placing the body above it [Plato] |
| Full Idea: When a man values beauty above virtue, the disrespect he shows his soul is total and fundamental, because he argues that the body is more to be honoured than the soul. | |
| From: Plato (The Laws [c.348 BCE], 727e) |
| 265 | An action is only just if it is performed by someone with a just character and outlook [Plato] |
| Full Idea: The description 'just' is applicable only to the benefit conferred or injury inflicted by someone with a just character and outlook. | |
| From: Plato (The Laws [c.348 BCE], 862b) | |
| A reaction: How should we describe the occasional administering of good justice by a generally wicked judge. Greeks focus on character, but moderns focus on actions. |
| 269 | Attempted murder is like real murder, but we should respect the luck which avoided total ruin [Plato] |
| Full Idea: An attempted murder should be treated like a successful one, but with respect shown for the luck which saved him from total ruin. | |
| From: Plato (The Laws [c.348 BCE], 877a) | |
| A reaction: The earliest reference to moral luck, I think. 'Repect' sounds vague, but it is asking judges to 'take it into consideration', which is quite practical. Attempted murderers are just as dangerous. |
| 240 | It would be strange if the gods rewarded those who experienced the most pleasure in life [Plato] |
| Full Idea: It would be strange if the gods gave the greatest rewards in heaven to those who led the most pleasant life, rather than the most just. | |
| From: Plato (The Laws [c.348 BCE], 662c) | |
| A reaction: All of philosophy is just footnotes to Plato.... See Idea 1454. |
| 264 | The conquest of pleasure is the noblest victory of all [Plato] |
| Full Idea: The conquest of pleasure is the noblest victory of all. | |
| From: Plato (The Laws [c.348 BCE], 840c) | |
| A reaction: Plato's puritanical streak. Even Aristotle doesn't agree with this. Self-control does not imply conquest of pleasure. Has a good professional wine taster conquered pleasure? |
| 4332 | Virtue is a concord of reason and emotion, with pleasure and pain trained to correct ends [Plato] |
| Full Idea: Virtue is the general concord of reason and emotion, but there is one key element, which is the correct formation of our feelings of pleasure and pain, which makes us hate what we ought to hate, and love what we ought to love. | |
| From: Plato (The Laws [c.348 BCE], 653c) | |
| A reaction: An important truth, taken up by Aristotle. To see another person humiliated gives some people pleasure and other people pain. |
| 248 | A serious desire for moral excellence is very rare indeed [Plato] |
| Full Idea: People who are anxious to attain moral excellence with all possible speed are pretty thin on the ground. | |
| From: Plato (The Laws [c.348 BCE], 718e) |
| 253 | Every crime is the result of excessive self-love [Plato] |
| Full Idea: The cause of each and every crime we commit is precisely this excessive love of ourselves. | |
| From: Plato (The Laws [c.348 BCE], 731e) |
| 263 | The only worthwhile life is one devoted to physical and moral perfection [Plato] |
| Full Idea: A life devoted to every physical perfection and every moral virtue is the only life worth the name. | |
| From: Plato (The Laws [c.348 BCE], 807c) |
| 235 | Virtue is the aim of all laws [Plato] |
| Full Idea: Virtue is the aim of the laws the legislator lays down. | |
| From: Plato (The Laws [c.348 BCE], 631a) |
| 277 | The Guardians must aim to discover the common element in the four cardinal virtues [Plato] |
| Full Idea: The guardians of the state should aim to get an exact idea of the common element in all the four virtues. | |
| From: Plato (The Laws [c.348 BCE], 965d) |
| 254 | Excessive laughter and tears must be avoided [Plato] |
| Full Idea: Excessive laughter and tears must be avoided. | |
| From: Plato (The Laws [c.348 BCE], 732c) |
| 266 | Injustice is the mastery of the soul by bad feelings, even if they do not lead to harm [Plato] |
| Full Idea: My general description of injustice is this: the mastery of the soul by anger, fear, pleasure, pain, envy and desires, whether they lead to actual damage or not. | |
| From: Plato (The Laws [c.348 BCE], 863e) |
| 242 | The best people are produced where there is no excess of wealth or poverty [Plato] |
| Full Idea: The community in which neither wealth nor poverty exists will produce the finest characters. | |
| From: Plato (The Laws [c.348 BCE], 679b) |
| 256 | Virtue and great wealth are incompatible [Plato] |
| Full Idea: Virtue and great wealth are quite incompatible. | |
| From: Plato (The Laws [c.348 BCE], 742e) |
| 245 | Totalitarian states destroy friendships and community spirit [Plato] |
| Full Idea: Excessively authoritarian government destroys all friendship and community of spirit in the state. | |
| From: Plato (The Laws [c.348 BCE], 697d) |
| 239 | Education in virtue produces citizens who are active but obedient [Plato] |
| Full Idea: Education in virtue produces a keen desire to become a perfect citizen who knows how to rule and be ruled as justice demands. | |
| From: Plato (The Laws [c.348 BCE], 643e) |
| 1402 | Friendship is impossible between master and slave, even if they are made equal [Plato] |
| Full Idea: Even if you proclaim that a master and a slave shall have equal status, friendship between them is inherently impossible. | |
| From: Plato (The Laws [c.348 BCE], 757a) |
| 262 | Men and women should qualify equally for honours on merit [Plato] |
| Full Idea: Men and women who have shown conspicuous merit should qualify for all honours without distinction of sex. | |
| From: Plato (The Laws [c.348 BCE], 802a) |
| 236 | Sound laws achieve the happiness of those who observe them [Plato] |
| Full Idea: Sound laws achieve the happiness of those who observe them. | |
| From: Plato (The Laws [c.348 BCE], 631b) |
| 259 | Justice is granting the equality which unequals deserve [Plato] |
| Full Idea: Justice consists of granting the 'equality' which unequals deserve to get. | |
| From: Plato (The Laws [c.348 BCE], 757d) | |
| A reaction: Beautifully simple, and hard to improve on. It shows the close link between equality and justice, but shows why they are not the same. The main debate about justice concerns the criteria for 'deserving'. |
| 238 | Children's games should channel their pleasures into adult activity [Plato] |
| Full Idea: We should use children's games to channel their pleasures and desires towards activities in which they will have to engage when they are adult. | |
| From: Plato (The Laws [c.348 BCE], 643c) |
| 260 | Control of education is the key office of state, and should go to the best citizen [Plato] |
| Full Idea: The Minister of Education is by far the most important of all the supreme offices of the state; the best all-round citizen in the state should be appointed. | |
| From: Plato (The Laws [c.348 BCE], 765e) |
| 257 | Mathematics has the widest application of any subject on the curriculum [Plato] |
| Full Idea: For domestic and public purposes, and all professional skills, no branch of a child's education has as big a range of applications as mathematics. | |
| From: Plato (The Laws [c.348 BCE], 747a) |
| 4331 | Education is channelling a child's feelings into the right course before it understands why [Plato] |
| Full Idea: I call 'education' the initial acquisition of virtue by the child, when the feelings of pleasure and affection, pain and hatred, are channelled in the right courses before he can understand the reason why. | |
| From: Plato (The Laws [c.348 BCE], 653b) | |
| A reaction: A precursor of Aristotle's view (Ethics 1104b11). A profound, simple and important insight. |
| 250 | The best way to educate the young is not to rebuke them, but to set a good example [Plato] |
| Full Idea: The best way to educate the younger generation (as well as yourself) is not to rebuke them but patently to practise all your life what you preach to others. | |
| From: Plato (The Laws [c.348 BCE], 729c) |
| 275 | Creation is not for you; you exist for the sake of creation [Plato] |
| Full Idea: Creation is not for your benefit; you exist for the sake of the universe. | |
| From: Plato (The Laws [c.348 BCE], 903c) |
| 10683 | We could ignore space, and just talk of the shape of matter [Hossack] |
| Full Idea: We might dispense with substantival space, and say that if the distribution of matter in space could have been different, that just means the matter of the Universe could have been shaped differently (with geometry as the science of shapes). | |
| From: Keith Hossack (Plurals and Complexes [2000], 9) |
| 273 | Movement is transmitted through everything, and it must have started with self-generated motion [Plato] |
| Full Idea: Motion is transmitted to innumerable things, and this must spring from some initial principle, which must be the change effected by self-generated motion. | |
| From: Plato (The Laws [c.348 BCE], 895a) |
| 8004 | In 'The Laws', to obey the law is to be obey god [Plato, by MacIntyre] |
| Full Idea: The divine is important in 'The Laws' because it is identified with law; to be obedient before the law is to be obedient before god. | |
| From: report of Plato (The Laws [c.348 BCE]) by Alasdair MacIntyre - A Short History of Ethics Ch.6 | |
| A reaction: Christian conservativism in a nutshell. Plato is rejecting his view in Euthyphro that piety (etc.) must precede the will of the gods. The obvious problem is bad laws, made by corrupt rulers. |
| 21261 | Self-moving soul has to be the oldest thing there is [Plato] |
| Full Idea: Soul, being the source of motion, is the most ancient thing there is. | |
| From: Plato (The Laws [c.348 BCE], 896b) | |
| A reaction: Plato seems to assume that the First Mover must still exist, which doesn't follow from anything in the argument. The First Pusher could be dead before the last domino falls. Why can't activity be the default state of everything? |
| 21257 | Self-generating motion is clearly superior to all other kinds of motion [Plato] |
| Full Idea: We can't resist the conclusion that the motion which can generate itself is infinitely superior, and all the others are inferior to it. | |
| From: Plato (The Laws [c.348 BCE], 894d) | |
| A reaction: Who said you can't get values from facts! Not that the argument depends on superiority. There could be an inferior First Mover, as a bus driver is subservient to the passengers, or (my favourite) a head teacher is inferior to the pupils. |
| 21258 | The only possible beginning for the endless motions of reality is something self-generated [Plato] |
| Full Idea: When the motion in reality is transmitted to thousands of things one after another, the entire sequence of their movements must surely spring from some initial principle, which can hardly be anything except the change effected by self-generated motion. | |
| From: Plato (The Laws [c.348 BCE], 895a) | |
| A reaction: This gives a domino picture of reality, with all of reality responding inertly to a first kick. Much better is to see self-generated motion in the active qualities of all matter, as seen in the sea of virtual subatomic particles at the smallest level. |
| 274 | Soul must be the cause of all the opposites, such as good and evil or beauty and ugliness [Plato] |
| Full Idea: Soul must be cause of good and evil, beauty and ugliness, justice and injustice, and all the opposites. | |
| From: Plato (The Laws [c.348 BCE], 896d) |
| 21263 | If all the motions of nature reflect calculations of reason, then the best kind of soul must direct it [Plato] |
| Full Idea: If the movement of the heavens and all that is in them reflects the motion and revolution and calculation of reason ...then clearly we have to admit that it is the best kind of soul that cares for the entire universe and directs it along the best path. | |
| From: Plato (The Laws [c.348 BCE], 897c) | |
| A reaction: Most of this passage reflects the cosmological argument - that without some initiating source natural events could not occur - but this slides into the design argument. So who designed mud (which is too inferior to have a Form)? |
| 278 | If astronomical movements are seen as necessary instead of by divine will, this leads to atheism [Plato] |
| Full Idea: If a man studying astronomy sees events apparently happening by necessity rather than being directed by the intention of a benevolent will, he will turn into an atheist. | |
| From: Plato (The Laws [c.348 BCE], 967a) |
| 21265 | The heavens must be full of gods, controlling nature either externally or from within [Plato] |
| Full Idea: A soul or souls have been shown to be cause of all the phenomena, and whether it is by their living presence in matter that they direct all the heavens, or by some other means, we insist that these souls are gods. So 'everything is full of gods'. | |
| From: Plato (The Laws [c.348 BCE], 899b) | |
| A reaction: This seems to have little to do with the pagan gods on Olympus. It is also notably not monotheistic. It is somewhere between animism and panpsychism. Does he think the rivers and woods contain gods? Probably not. Just the orderly heavens. |
| 21262 | There must be at least two souls controlling the cosmos, one doing good, the other the opposite [Plato] |
| Full Idea: There must be more than one soul (not fewer than two) controlling movement and the heavens: that which does good, and that which has the opposite capacity. | |
| From: Plato (The Laws [c.348 BCE], 896e) | |
| A reaction: [Wording compressed - as often with the dialogues] This idea of controlling opposites is found in Empedocles. Presumably this good soul defers to the Form of the Good, as implied by the Euthyphro Question. |