46 ideas
| 15845 | It seems absurd that seeing a person's limbs, the one is many, and yet the many are one [Plato] |
| Full Idea: Someone first distinguishes a person's limbs and parts and asks your agreement that all the parts are identical with that unity, then ridicules you that you have to admit one is many, and indefinitely many, and again that the many are only only one thing. | |
| From: Plato (Philebus [c.353 BCE], 14e) | |
| A reaction: This is a passing aporia, but actually seems to approach the central mystery of the metaphysics of identity. A thing can't be a 'unity' if there are not things to unify? So what sorts of 'unification' are there? |
| 18739 | Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) [Horsten/Pettigrew] |
| Full Idea: Three periods can be distinguished in philosophical logic: the syntactic stage, from Russell's definite descriptions to the 1950s, the dominance of possible world semantics from the 50s to 80s, and a current widening of the subject. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 1) | |
| A reaction: [compressed] I've read elsewhere that the arrival of Tarski's account of truth in 1933, taking things beyond the syntactic, was also a landmark. |
| 18741 | Logical formalization makes concepts precise, and also shows their interrelation [Horsten/Pettigrew] |
| Full Idea: Logical formalization forces the investigator to make the central philosophical concepts precise. It can also show how some philosophical concepts and objects can be defined in terms of others. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2) | |
| A reaction: This is the main rationale of the highly formal and mathematical approach to such things. The downside is when you impose 'precision' on language that was never intended to be precise. |
| 18744 | Models are sets with functions and relations, and truth built up from the components [Horsten/Pettigrew] |
| Full Idea: A (logical) model is a set with functions and relations defined on it that specify the denotation of the non-logical vocabulary. A series of recursive clauses explicate how truth values of complex sentences are compositionally determined from the parts. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: See the ideas on 'Functions in logic' and 'Relations in logic' (in the alphabetical list) to expand this important idea. |
| 9867 | It is absurd to define a circle, but not be able to recognise a real one [Plato] |
| Full Idea: It will be ridiculous if our student knows the definition of the circle and of the divine sphere itself, but cannot recognize the human sphere and these our circles, used in housebuilding. | |
| From: Plato (Philebus [c.353 BCE], 62a) | |
| A reaction: This is the equivalent of being able to recite numbers, but not to count objects. It also resembles Molyneux's question (to Locke), of whether recognition by one sense entails recognition by others. Nice (and a bit anti-platonist!). |
| 9865 | Daily arithmetic counts unequal things, but pure arithmetic equalises them [Plato] |
| Full Idea: The arithmetic of the many computes sums of unequal units, such as two armies, or two herds, ..but philosopher's arithmetic computes when it is guaranteed that none of those infinitely many units differed in the least from any of the others. | |
| From: Plato (Philebus [c.353 BCE], 56d) | |
| A reaction: But of course 'the many' are ironing out the differences too, when they say there are 'three armies'. Shocking snob, Plato. Even philosophers are interested in the difference between three armies and three platoons. |
| 18740 | If 'exist' doesn't express a property, we can hardly ask for its essence [Horsten/Pettigrew] |
| Full Idea: If there is indeed no property of existence that is expressed by the word 'exist', then it makes no sense to ask for its essence. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2) | |
| A reaction: As far as I can tell, this was exactly Aristotle's conclusion, so he skirted round the question of 'being qua being', and focused on the nature of objects instead. Grand continental talk of 'Being' doesn't sound very interesting. |
| 14503 | If a mixture does not contain measure and proportion, it is corrupted and destroyed [Plato] |
| Full Idea: Any kind of mixture that does not ...possess measure or the nature of proportion will necessarily corrupt its ingredients and most of all itself. For there would be no blending in such cases but really an unconnected medley, and ruin what contains it. | |
| From: Plato (Philebus [c.353 BCE], 64d) | |
| A reaction: My guess is that Plato is thinking of the decay of living things when they die, losing the proportions of psuché, and then applying this to the unity of inanimate objects as well. One might compare Leibniz's monads. |
| 15857 | Any mixture which lacks measure and proportion doesn't even count as a mixture at all [Plato] |
| Full Idea: Any blend [mixture] which does not have measure or the nature of proportion in any way whatsoever, of necessity destroys both its ingredients and, primarily, itself. It is truly no blend at all, but a kind of unblended disaster. | |
| From: Plato (Philebus [c.353 BCE], 64e) | |
| A reaction: Obviously there can be chaotic mixtures, but I guess Plato is picking out mixtures about which we can say something |
| 13076 | Scholastics treat relations as two separate predicates of the relata [Cover/O'Leary-Hawthorne] |
| Full Idea: The scholastics treated it as a step in the right explanatory direction to analyze a relational statement of the form 'aRb' into two subject-predicate statements, attributing different relational predicates to a and to b. | |
| From: Cover,J/O'Leary-Hawthorne,J (Substance and Individuation in Leibniz [1999], 2.2.1) | |
| A reaction: The only alternative seems to be Russell's view of relations as pure universals, having a life of their own, quite apart from their relata. Or you could take them as properties of space, time (and powers?), external to the relata? |
| 4447 | If the good is one, is it unchanged when it is in particulars, and is it then separated from itself? [Plato] |
| Full Idea: If man is one, and the good is one, how are they supposed to exist? Do they stay the same even though they are found in many things at the same time, and are they then entirely separated from themselves, which seems most impossible of all? | |
| From: Plato (Philebus [c.353 BCE], 15a) | |
| A reaction: Presumably Plato anguishes over this because he thinks Forms are self-predicating (the Good is good). Big mistake. The Good fathers good particulars which resemble itself, but are diluted? |
| 13102 | If you individuate things by their origin, you still have to individuate the origins themselves [Cover/O'Leary-Hawthorne] |
| Full Idea: If we go for the necessity-of-origins view, A and B are different if the origin of A is different from the origin of B. But one is left with the further question 'When is the origin of A distinct from the origin of B?' | |
| From: Cover,J/O'Leary-Hawthorne,J (Substance and Individuation in Leibniz [1999], 7.4.1) | |
| A reaction: There may be an answer to this, in a regress of origins that support one another, but in the end the objection is obviously good. You can't begin to refer to an 'origin' if you can't identify anything in the first place. |
| 13103 | Numerical difference is a symmetrical notion, unlike proper individuation [Cover/O'Leary-Hawthorne] |
| Full Idea: Scholastics distinguished criteria of numerical difference from questions of individuation proper, since numerical difference is a symmetrical notion. | |
| From: Cover,J/O'Leary-Hawthorne,J (Substance and Individuation in Leibniz [1999], 7.4.1) | |
| A reaction: This apparently old-fashioned point appears to be conclusively correct. Modern thinkers, though, aren't comfortable with proper individuation, because they don't believe in concepts like 'essence' and 'substance' that are needed for the job. |
| 13104 | Haecceity as property, or as colourless thisness, or as singleton set [Cover/O'Leary-Hawthorne] |
| Full Idea: There is a contemporary property construal of haecceities, ...and a Scotistic construal as primitive, 'colourless' thisnesses which, unlike singleton-set haecceities, are aimed to do some explanatory work. | |
| From: Cover,J/O'Leary-Hawthorne,J (Substance and Individuation in Leibniz [1999], 7.4.4) | |
| A reaction: [He associates the contemporary account with David Kaplan] I suppose I would say that individuation is done by properties, but not by some single property, so I take it that I don't believe in haecceities at all. What individuates a haecceity? |
| 15856 | A thing can become one or many, depending on how we talk about it [Plato] |
| Full Idea: It is through discourse that the same thing flits around, becoming one and many in all sorts of ways. | |
| From: Plato (Philebus [c.353 BCE], 15d) | |
| A reaction: This is not scepticism about wholes on Plato's part, but a reminder of an obvious fact, that in thought we can break the world up and put it back together again. It is a touchstone of the debate, though. |
| 13100 | Maybe 'substance' is more of a mass-noun than a count-noun [Cover/O'Leary-Hawthorne] |
| Full Idea: We could think of 'substance' on the model of a mass noun, rather than a count noun. | |
| From: Cover,J/O'Leary-Hawthorne,J (Substance and Individuation in Leibniz [1999], 7.3) | |
| A reaction: They offer this to help Leibniz out of a mess, but I think he would be appalled. The proposal seems close to 'prime matter' in Aristotle, which never quite does the job required of it. The idea is nice, though, and should be taken seriously. |
| 13068 | We can ask for the nature of substance, about type of substance, and about individual substances [Cover/O'Leary-Hawthorne] |
| Full Idea: In the 'blueprint' approach to substance, we confront at least three questions: What is it for a thing to be an individual substance? What is it for a thing to be the kind of substance that it is? What is it to be that very individual substance? | |
| From: Cover,J/O'Leary-Hawthorne,J (Substance and Individuation in Leibniz [1999], 1.1.1) | |
| A reaction: My working view is that the answer to the first question is that substance is essence, that the second question is overrated and parasitic on the third, and that the third is the key question, and also reduces to essence. |
| 13069 | The general assumption is that substances cannot possibly be non-substances [Cover/O'Leary-Hawthorne] |
| Full Idea: There is a widespread assumption, now and in the past, that substances are essentially substances: nothing is actually a substance but possibly a non-substance. | |
| From: Cover,J/O'Leary-Hawthorne,J (Substance and Individuation in Leibniz [1999], 1.1.2) | |
| A reaction: It seems to me that they clearly mean, in this context, that substances are 'necessarily' substances, not that they are 'essentially' substances. I would just say that substances are essences, and leave the necessity question open. |
| 374 | If one object is divided into its parts, someone can then say that one are many and many is one [Plato] |
| Full Idea: Someone can theoretically divide an object into constituent parts, concede that they are one object, and then claim that therefore the one is many and the many are one. | |
| From: Plato (Philebus [c.353 BCE], 14e) |
| 13072 | Modern essences are sets of essential predicate-functions [Cover/O'Leary-Hawthorne] |
| Full Idea: The modern view of essence is that the essence of a particular thing is given by the set of predicate-functions essential to it, and the essence of any kind is given by the set of predicate-functions essential to every possible member of that kind. | |
| From: Cover,J/O'Leary-Hawthorne,J (Substance and Individuation in Leibniz [1999], 1.2.2) | |
| A reaction: Thus the modern view has elided the meanings of 'essential' and 'necessary' when talking of properties. They are said to be 'functions' from possible worlds to individuals. The old view (and mine) demands real essences, not necessary properties. |
| 17080 | Modern essentialists express essence as functions from worlds to extensions for predicates [Cover/O'Leary-Hawthorne] |
| Full Idea: The modern essentialist gives the same metaphysical treatment to every grammatical predicate - by associating a function from worlds to extensions for each. | |
| From: Cover,J/O'Leary-Hawthorne,J (Substance and Individuation in Leibniz [1999], 2.2) | |
| A reaction: I take this to mean that essentialism is the view that if some predicate attaches to an object then that predicate is essential if there is an extension of that predicate in all possible worlds. In English, essential predicates are necessary predicates. |
| 13101 | Necessity-of-origin won't distinguish ex nihilo creations, or things sharing an origin [Cover/O'Leary-Hawthorne] |
| Full Idea: A necessity-of-origins approach cannot work to distinguish things that come into being genuinely ex nihilo, and cannot work to distinguish things sharing a single origin. | |
| From: Cover,J/O'Leary-Hawthorne,J (Substance and Individuation in Leibniz [1999], 7.4.1) | |
| A reaction: Since I am deeply suspicious of essentiality or necessity of origin (and they are not, I presume, the same thing) I like these two. Twins have always bothered me with the second case (where order of birth seems irrelevant). |
| 18745 | A Tarskian model can be seen as a possible state of affairs [Horsten/Pettigrew] |
| Full Idea: A Tarskian model can in a sense be seen as a model of a possible state of affairs. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: I include this remark to show how possible worlds semantics built on the arrival of model theory. |
| 18747 | The 'spheres model' was added to possible worlds, to cope with counterfactuals [Horsten/Pettigrew] |
| Full Idea: The notion of a possible worlds model was extended (resulting in the concept of a 'spheres model') in order to obtain a satisfactory logical treatment of counterfactual conditional sentences. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4) | |
| A reaction: Thus we add 'centred' worlds, and an 'actual' world, to the loose original model. It is important to remember when we discuss 'close' worlds that we are then committed to these presuppositions. |
| 18748 | Epistemic logic introduced impossible worlds [Horsten/Pettigrew] |
| Full Idea: The idea of 'impossible worlds' was introduced into epistemic logic. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4) | |
| A reaction: Nathan Salmon seems interested in their role in metaphysics (presumably in relation to Meinongian impossible objects, like circular squares, which must necessarily be circular). |
| 18746 | Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment [Horsten/Pettigrew] |
| Full Idea: Each possible worlds model contains a set of possible worlds. For this reason, possible worlds semantics is often charged with smuggling in heavy metaphysical commitments. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: To a beginner it looks very odd that you should try to explain possibility by constructing a model of it in terms of 'possible' worlds. |
| 18750 | Using possible worlds for knowledge and morality may be a step too far [Horsten/Pettigrew] |
| Full Idea: When the possible worlds semantics were further extended to model notions of knowledge and of moral obligation, the application was beginning to look distinctly forced and artificial. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 5) | |
| A reaction: They accept lots of successes in modelling necessity and time. |
| 13081 | Even extreme modal realists might allow transworld identity for abstract objects [Cover/O'Leary-Hawthorne] |
| Full Idea: It might be suggested that even the extreme modal realist can countenance transworld identity for abstract objects. | |
| From: Cover,J/O'Leary-Hawthorne,J (Substance and Individuation in Leibniz [1999], 3.2.2 n46) | |
| A reaction: This may sound right for uncontroversial or well-defined abstracta such as numbers and circles, but even 'or' is ambiguous, and heaven knows what the transworld identity of 'democracy' is! |
| 389 | How can you be certain about aspects of the world if they aren't constant? [Plato] |
| Full Idea: Could we attribute certainty to studying aspects of the world, such as how it arose, or acts, or is acted upon, when none of them ever was or will be constant? Of course not. | |
| From: Plato (Philebus [c.353 BCE], 59b) |
| 13071 | We can go beyond mere causal explanations if we believe in an 'order of being' [Cover/O'Leary-Hawthorne] |
| Full Idea: The philosopher comfortable with an 'order of being' has richer resources to make sense of the 'in virtue of' relation than that provided only by causal relations between states of affairs, positing in addition other sorts of explanatory relationships. | |
| From: Cover,J/O'Leary-Hawthorne,J (Substance and Individuation in Leibniz [1999], 1.1.2) | |
| A reaction: This might best be characterised as 'ontological dependence', and could be seen as a non-causal but fundamental explanatory relationship, and not one that has to depend on a theistic world view. |
| 390 | If goodness involves moderation and proportion, then it seems to be found in beauty [Plato] |
| Full Idea: Moderation and proportion seem, in effect, to be beauty and excellence. So now this property we're looking for, goodness, has taken refuge in beauty. | |
| From: Plato (Philebus [c.353 BCE], 64e) |
| 391 | The good involves beauty, proportion and truth [Plato] |
| Full Idea: If we are unable to net the good in a single concept, three must capture it: namely, beauty, proportion and truth. | |
| From: Plato (Philebus [c.353 BCE], 65a) | |
| A reaction: Very interesting. More illuminating than the discussion of the Good in 'Republic'. Is a handsome and honest murderer good? Is beauty part of the nature of the good, or a hallmark of it? |
| 392 | Neither intellect nor pleasure are the good, because they are not perfect and self-sufficient [Plato] |
| Full Idea: Both intellect and pleasure are completely absolved of being the good itself, since they both lack independence, that is, sufficiency and perfection. | |
| From: Plato (Philebus [c.353 BCE], 67a) | |
| A reaction: This seems to be Plato disagreeing with Socrates, who sees reason and intellect as central to morality. Presumable he means that the good should be a primitive. Why is pleasure not sufficient? |
| 393 | Good first, then beauty, then reason, then knowledge, then pleasure [Plato, by PG] |
| Full Idea: Good is supreme, followed by beauty, then reason, then knowledge, then pure pleasure, then mixed pleasure. | |
| From: report of Plato (Philebus [c.353 BCE], 67a) by PG - Db (ideas) | |
| A reaction: He tells us that pure pleasures are simple pleasures. Epicurus presumably read this. No mention of truth, unless that is part of reason. Why does he value beauty so highly? |
| 385 | Some of the pleasures and pains we feel are false [Plato] |
| Full Idea: Living beings experience pleasures and pains which seem, and indeed are, false. | |
| From: Plato (Philebus [c.353 BCE], 42c) | |
| A reaction: The idea that there are 'authentic' pleasures and pains needs some investigation. Misguided anger is a false pain? Vanity is a false pleasure? |
| 387 | A small pure pleasure is much finer than a large one contaminated with pain [Plato] |
| Full Idea: A tiny little pleasure is, if uncontaminated by pain, always more pleasant, truer and finer than a large amount. | |
| From: Plato (Philebus [c.353 BCE], 53b) | |
| A reaction: More Platonic puritanism. Is a complete absence of pleasure the highest pleasure of all? I don't think I understand 'truer'. Why would a pleasure be false because it is intense? |
| 373 | Pleasure is certainly very pleasant, but it doesn't follow that all pleasures are good [Plato] |
| Full Idea: The pleasantness of pleasure is not in dispute, but where we say the majority of pleasures are bad, though some are good, you are attributing goodness to all of them. | |
| From: Plato (Philebus [c.353 BCE], 13b) | |
| A reaction: Bentham's plausible view is that the feeling of pleasure is always good, and the badness is in some other aspect of the event. Compare sadistic fantasy with sadistic action. |
| 379 | The good must be sufficient and perfect, and neither intellect nor pleasure are that [Plato] |
| Full Idea: Neither pleasure nor intellect comprises the good. If it did it would have to be sufficient and perfect. | |
| From: Plato (Philebus [c.353 BCE], 22b) | |
| A reaction: Seems sensible. I can't make sense of any vision of the good which consists of suppressing some aspect of human nature. (Hm. Our capacity for violence?) |
| 371 | Reason, memory, truth and wisdom are far better than pleasure, for those who can attain them [Plato] |
| Full Idea: My contention is that reason, intellect, memory - along with correct belief and true calculation - are far better than pleasure for all creatures capable of attaining them. | |
| From: Plato (Philebus [c.353 BCE], 11b) | |
| A reaction: Why? Is it better to understand deeply, or to act well? Can we just say there is objective good and subjective good, and they have little in common? Depressed heroes. |
| 376 | Would you prefer a life of pleasure without reason, or one of reason without pleasure? [Plato] |
| Full Idea: Try thinking about the life of pleasure without reason, and the life of reason without pleasure. | |
| From: Plato (Philebus [c.353 BCE], 20e) | |
| A reaction: I suspect that we see the two as more deeply entangled that Plato did. It would be hard to motivate reasoning if we didn't enjoy it. Pleasure without reason sound dire. |
| 382 | It is unlikely that the gods feel either pleasure or pain [Plato] |
| Full Idea: It is unlikely that the gods feel pleasure or the opposite. | |
| From: Plato (Philebus [c.353 BCE], 33b) | |
| A reaction: Compare Idea 383. |
| 381 | We feel pleasure when we approach our natural state of harmony [Plato] |
| Full Idea: When harmony is being restored, and the natural state of harmony is approached, then pleasure arises. | |
| From: Plato (Philebus [c.353 BCE], 31d) | |
| A reaction: The supreme value of harmony was important to Plato, but most of us are less convinced, I suspect. The way to achieve harmony is to avoid anything stressful. |
| 386 | Intense pleasure and pain are not felt in a good body, but in a worthless one [Plato] |
| Full Idea: Intensity of pleasure and pain is to be found not in a good state of body and soul, but in a worthless one. | |
| From: Plato (Philebus [c.353 BCE], 45e) | |
| A reaction: This just seems to be Plato's puritanism. How can you criticise someone for experience genuine intense pain? Experiencing intense pleasure is no crime, but pursuit of it might be. |
| 388 | Hedonists must say that someone in pain is bad, even if they are virtuous [Plato] |
| Full Idea: A hedonist must say that someone who happens to be feeling pain rather than pleasure is, as long as the pain lasts, a bad man, even if he is the most virtuous man in the world. | |
| From: Plato (Philebus [c.353 BCE], 55b) |
| 377 | If you lived a life of maximum pleasure, would you still be lacking anything? [Plato] |
| Full Idea: Would you, Protarchus, gladly live your whole life experiencing only the greatest pleasure? Would you think you were still lacking anything? | |
| From: Plato (Philebus [c.353 BCE], 21a) | |
| A reaction: the pleasure machine problem |
| 378 | A life of pure pleasure with no intellect is the life of a jellyfish [Plato] |
| Full Idea: A life of pure pleasure with no intellect is not the life of a human being, but the life of a jellyfish. | |
| From: Plato (Philebus [c.353 BCE], 21c) |