78 ideas
| 20801 | A wise man's chief strength is not being tricked; nothing is worse than error, frivolity or rashness [Zeno of Citium, by Cicero] |
| Full Idea: Zeno held that the wise man's chief strength is that he is careful not to be tricked, and sees to it that he is not deceived; for nothing is more alien to the conception that we have of the seriousness of the wise man than error, frivolity or rashness. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by M. Tullius Cicero - Academica II.66 | |
| A reaction: I presume that this concerns being deceived by other people, and also being deceived by evidence. I suggest that the greatest ability of the wise person is the accurate assessment of evidence. |
| 13560 | A wise man is not subservient to anything [Seneca] |
| Full Idea: I do not call any man wise who is subservient to anything. | |
| From: Seneca the Younger (On the Happy Life [c.60], §11) | |
| A reaction: At the very least, a wise man should be subservient to a wiser man. |
| 1771 | When shown seven versions of the mowing argument, he paid twice the asking price for them [Zeno of Citium, by Diog. Laertius] |
| Full Idea: When shown seven species of dialectic in the mowing argument, he asked the price, and when told 'a hundred drachmas', he gave two hundred, so devoted was he to learning. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.Ze.20 | |
| A reaction: Wonderful. I have a watertight proof that pleasure is not the good, which I will auction on the internet. |
| 20770 | Philosophy has three parts, studying nature, character, and rational discourse [Zeno of Citium, by Diog. Laertius] |
| Full Idea: They say that philosophical theory is tripartite. For one part of it concerns nature [i.e. physics], another concerns character [i.e. ethics], and another concerns rational discourse [i.e. logic] | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.39 | |
| A reaction: Surely 'nature' included biology, and shouldn't be glossed as 'physics'? And I presume that 'rational discourse' is 'logos', rather than 'logic'. Interesting to see that ethics just is the study of character (and not of good and bad actions). |
| 6022 | Someone who says 'it is day' proposes it is day, and it is true if it is day [Zeno of Citium, by Diog. Laertius] |
| Full Idea: Someone who says 'It is day' seems to propose that it is day; if, then, it is day, the proposition advanced comes out true, but if not, it comes out false. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.65 | |
| A reaction: Those who find Tarski's theory annoyingly vacuous should note that the ancient Stoics thought the same point worth making. They seem to have clearly favoured some minimal account of truth, according to this. |
| 10987 | Three traditional names of rules are 'Simplification', 'Addition' and 'Disjunctive Syllogism' [Read] |
| Full Idea: Three traditional names for rules are 'Simplification' (P from 'P and Q'), 'Addition' ('P or Q' from P), and 'Disjunctive Syllogism' (Q from 'P or Q' and 'not-P'). | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 11004 | Necessity is provability in S4, and true in all worlds in S5 [Read] |
| Full Idea: In S4 necessity is said to be informal 'provability', and in S5 it is said to be 'true in every possible world'. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) | |
| A reaction: It seems that the S4 version is proof-theoretic, and the S5 version is semantic. |
| 11018 | There are fuzzy predicates (and sets), and fuzzy quantifiers and modifiers [Read] |
| Full Idea: In fuzzy logic, besides fuzzy predicates, which define fuzzy sets, there are also fuzzy quantifiers (such as 'most' and 'few') and fuzzy modifiers (such as 'usually'). | |
| From: Stephen Read (Thinking About Logic [1995], Ch.7) |
| 11011 | Same say there are positive, negative and neuter free logics [Read] |
| Full Idea: It is normal to classify free logics into three sorts; positive free logics (some propositions with empty terms are true), negative free logics (they are false), and neuter free logics (they lack truth-value), though I find this unhelpful and superficial. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.5) |
| 11020 | Realisms like the full Comprehension Principle, that all good concepts determine sets [Read] |
| Full Idea: Hard-headed realism tends to embrace the full Comprehension Principle, that every well-defined concept determines a set. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.8) | |
| A reaction: This sort of thing gets you into trouble with Russell's paradox (though that is presumably meant to be excluded somehow by 'well-defined'). There are lots of diluted Comprehension Principles. |
| 10986 | Not all validity is captured in first-order logic [Read] |
| Full Idea: We must recognise that first-order classical logic is inadequate to describe all valid consequences, that is, all cases in which it is impossible for the premisses to be true and the conclusion false. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: This is despite the fact that first-order logic is 'complete', in the sense that its own truths are all provable. |
| 10972 | The non-emptiness of the domain is characteristic of classical logic [Read] |
| Full Idea: The non-emptiness of the domain is characteristic of classical logic. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 11024 | Semantics must precede proof in higher-order logics, since they are incomplete [Read] |
| Full Idea: For the realist, study of semantic structures comes before study of proofs. In higher-order logic is has to, for the logics are incomplete. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.9) | |
| A reaction: This seems to be an important general observation about any incomplete system, such as Peano arithmetic. You may dream the old rationalist dream of starting from the beginning and proving everything, but you can't. Start with truth and meaning. |
| 10985 | We should exclude second-order logic, precisely because it captures arithmetic [Read] |
| Full Idea: Those who believe mathematics goes beyond logic use that fact to argue that classical logic is right to exclude second-order logic. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10970 | A theory of logical consequence is a conceptual analysis, and a set of validity techniques [Read] |
| Full Idea: A theory of logical consequence, while requiring a conceptual analysis of consequence, also searches for a set of techniques to determine the validity of particular arguments. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10984 | Logical consequence isn't just a matter of form; it depends on connections like round-square [Read] |
| Full Idea: If classical logic insists that logical consequence is just a matter of the form, we fail to include as valid consequences those inferences whose correctness depends on the connections between non-logical terms (such as 'round' and 'square'). | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: He suggests that an inference such as 'round, so not square' should be labelled as 'materially valid'. |
| 10973 | A theory is logically closed, which means infinite premisses [Read] |
| Full Idea: A 'theory' is any logically closed set of propositions, ..and since any proposition has infinitely many consequences, including all the logical truths, so that theories have infinitely many premisses. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: Read is introducing this as the essential preliminary to an account of the Compactness Theorem, which relates these infinite premisses to the finite. |
| 11007 | Quantifiers are second-order predicates [Read] |
| Full Idea: Quantifiers are second-order predicates. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.5) | |
| A reaction: [He calls this 'Frege's insight'] They seem to be second-order in Tarski's sense, that they are part of a metalanguage about the sentence, rather than being a part of the sentence. |
| 10978 | In second-order logic the higher-order variables range over all the properties of the objects [Read] |
| Full Idea: The defining factor of second-order logic is that, while the domain of its individual variables may be arbitrary, the range of the first-order variables is all the properties of the objects in its domain (or, thinking extensionally, of the sets objects). | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: The key point is that the domain is 'all' of the properties. How many properties does an object have. You need to decide whether you believe in sparse or abundant properties (I vote for very sparse indeed). |
| 10971 | A logical truth is the conclusion of a valid inference with no premisses [Read] |
| Full Idea: Logical truth is a degenerate, or extreme, case of consequence. A logical truth is the conclusion of a valid inference with no premisses, or a proposition in the premisses of an argument which is unnecessary or may be suppressed. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10988 | Any first-order theory of sets is inadequate [Read] |
| Full Idea: Any first-order theory of sets is inadequate because of the Löwenheim-Skolem-Tarski property, and the consequent Skolem paradox. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: The limitation is in giving an account of infinities. |
| 10974 | Compactness is when any consequence of infinite propositions is the consequence of a finite subset [Read] |
| Full Idea: Classical logical consequence is compact, which means that any consequence of an infinite set of propositions (such as a theory) is a consequence of some finite subset of them. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10975 | Compactness does not deny that an inference can have infinitely many premisses [Read] |
| Full Idea: Compactness does not deny that an inference can have infinitely many premisses. It can; but classically, it is valid if and only if the conclusion follows from a finite subset of them. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10977 | Compactness blocks the proof of 'for every n, A(n)' (as the proof would be infinite) [Read] |
| Full Idea: Compact consequence undergenerates - there are intuitively valid consequences which it marks as invalid, such as the ω-rule, that if A holds of the natural numbers, then 'for every n, A(n)', but the proof of that would be infinite, for each number. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10976 | Compactness makes consequence manageable, but restricts expressive power [Read] |
| Full Idea: Compactness is a virtue - it makes the consequence relation more manageable; but it is also a limitation - it limits the expressive power of the logic. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: The major limitation is that wholly infinite proofs are not permitted, as in Idea 10977. |
| 11014 | Self-reference paradoxes seem to arise only when falsity is involved [Read] |
| Full Idea: It cannot be self-reference alone that is at fault. Rather, what seems to cause the problems in the paradoxes is the combination of self-reference with falsity. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.6) |
| 7555 | Zeno achieved the statement of the problems of infinitesimals, infinity and continuity [Russell on Zeno of Citium] |
| Full Idea: Zeno was concerned with three increasingly abstract problems of motion: the infinitesimal, the infinite, and continuity; to state the problems is perhaps the hardest part of the philosophical task, and this was done by Zeno. | |
| From: comment on Zeno (Citium) (fragments/reports [c.294 BCE]) by Bertrand Russell - Mathematics and the Metaphysicians p.81 | |
| A reaction: A very nice tribute, and a beautiful clarification of what Zeno was concerned with. |
| 11025 | Infinite cuts and successors seems to suggest an actual infinity there waiting for us [Read] |
| Full Idea: Every potential infinity seems to suggest an actual infinity - e.g. generating successors suggests they are really all there already; cutting the line suggests that the point where the cut is made is already in place. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.8) | |
| A reaction: Finding a new gambit in chess suggests it was there waiting for us, but we obviously invented chess. Daft. |
| 10979 | Although second-order arithmetic is incomplete, it can fully model normal arithmetic [Read] |
| Full Idea: Second-order arithmetic is categorical - indeed, there is a single formula of second-order logic whose only model is the standard model ω, consisting of just the natural numbers, with all of arithmetic following. It is nevertheless incomplete. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: This is the main reason why second-order logic has a big fan club, despite the logic being incomplete (as well as the arithmetic). |
| 10980 | Second-order arithmetic covers all properties, ensuring categoricity [Read] |
| Full Idea: Second-order arithmetic can rule out the non-standard models (with non-standard numbers). Its induction axiom crucially refers to 'any' property, which gives the needed categoricity for the models. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10997 | Von Neumann numbers are helpful, but don't correctly describe numbers [Read] |
| Full Idea: The Von Neumann numbers have a structural isomorphism to the natural numbers - each number is the set of all its predecessors, so 2 is the set of 0 and 1. This helps proofs, but is unacceptable. 2 is not a set with two members, or a member of 3. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) |
| 20860 | Whatever participates in substance exists [Zeno of Citium, by Stobaeus] |
| Full Idea: Zeno says that whatever participates in substance exists. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by John Stobaeus - Anthology 2.05a | |
| A reaction: This seems Aristotelian, implying that only objects exist. Unformed stuff would not normally qualify as a 'substance'. So does mud exist? See the ideas of Henry Laycock. |
| 11016 | Would a language without vagueness be usable at all? [Read] |
| Full Idea: We must ask whether a language without vagueness would be usable at all. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.7) | |
| A reaction: Popper makes a similar remark somewhere, with which I heartily agreed. This is the idea of 'spreading the word' over the world, which seems the right way of understanding it. |
| 11019 | Supervaluations say there is a cut-off somewhere, but at no particular place [Read] |
| Full Idea: The supervaluation approach to vagueness is to construe vague predicates not as ones with fuzzy borderlines and no cut-off, but as having a cut-off somewhere, but in no particular place. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.7) | |
| A reaction: Presumably you narrow down the gap by supervaluation, then split the difference to get a definite value. |
| 11012 | A 'supervaluation' gives a proposition consistent truth-value for classical assignments [Read] |
| Full Idea: A 'supervaluation' says a proposition is true if it is true in all classical extensions of the original partial valuation. Thus 'A or not-A' has no valuation for an empty name, but if 'extended' to make A true or not-true, not-A always has opposite value. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.5) |
| 11013 | Identities and the Indiscernibility of Identicals don't work with supervaluations [Read] |
| Full Idea: In supervaluations, the Law of Identity has no value for empty names, and remains so if extended. The Indiscernibility of Identicals also fails if extending it for non-denoting terms, where Fa comes out true and Fb false. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.5) |
| 10995 | A haecceity is a set of individual properties, essential to each thing [Read] |
| Full Idea: The haecceitist (a neologism coined by Duns Scotus, pronounced 'hex-ee-it-ist', meaning literally 'thisness') believes that each thing has an individual essence, a set of properties which are essential to it. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) | |
| A reaction: This seems to be a difference of opinion over whether a haecceity is a set of essential properties, or a bare particular. The key point is that it is unique to each entity. |
| 11001 | Equating necessity with truth in every possible world is the S5 conception of necessity [Read] |
| Full Idea: The equation of 'necessity' with 'true in every possible world' is known as the S5 conception, corresponding to the strongest of C.I.Lewis's five modal systems. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) | |
| A reaction: Are the worlds naturally, or metaphysically, or logically possible? |
| 10992 | The point of conditionals is to show that one will accept modus ponens [Read] |
| Full Idea: The point of conditionals is to show that one will accept modus ponens. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.3) | |
| A reaction: [He attributes this idea to Frank Jackson] This makes the point, against Grice, that the implication of conditionals is not conversational but a matter of logical convention. See Idea 21396 for a very different view. |
| 10989 | The standard view of conditionals is that they are truth-functional [Read] |
| Full Idea: The standard view of conditionals is that they are truth-functional, that is, that their truth-values are determined by the truth-values of their constituents. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.3) |
| 11017 | Some people even claim that conditionals do not express propositions [Read] |
| Full Idea: Some people even claim that conditionals do not express propositions. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.7) | |
| A reaction: See Idea 14283, where this appears to have been 'proved' by Lewis, and is not just a view held by some people. |
| 10983 | Knowledge of possible worlds is not causal, but is an ontology entailed by semantics [Read] |
| Full Idea: The modal Platonist denies that knowledge always depends on a causal relation. The reality of possible worlds is an ontological requirement, to secure the truth-values of modal propositions. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: [Reply to Idea 10982] This seems to be a case of deriving your metaphyics from your semantics, of which David Lewis seems to be guilty, and which strikes me as misguided. |
| 10982 | How can modal Platonists know the truth of a modal proposition? [Read] |
| Full Idea: If modal Platonism was true, how could we ever know the truth of a modal proposition? | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: I take this to be very important. Our knowledge of modal truths must depend on our knowledge of the actual world. The best answer seems to involve reference to the 'powers' of the actual world. A reply is in Idea 10983. |
| 10996 | Actualism is reductionist (to parts of actuality), or moderate realist (accepting real abstractions) [Read] |
| Full Idea: There are two main forms of actualism: reductionism, which seeks to construct possible worlds out of some more mundane material; and moderate realism, in which the actual concrete world is contrasted with abstract, but none the less real, possible worlds. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) | |
| A reaction: I am a reductionist, as I do not take abstractions to be 'real' (precisely because they have been 'abstracted' from the things that are real). I think I will call myself a 'scientific modalist' - we build worlds from possibilities, discovered by science. |
| 10981 | A possible world is a determination of the truth-values of all propositions of a domain [Read] |
| Full Idea: A possible world is a complete determination of the truth-values of all propositions over a certain domain. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: Even if the domain is very small? Even if the world fitted the logic nicely, but was naturally impossible? |
| 11000 | If worlds are concrete, objects can't be present in more than one, and can only have counterparts [Read] |
| Full Idea: If each possible world constitutes a concrete reality, then no object can be present in more than one world - objects may have 'counterparts', but cannot be identical with them. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) | |
| A reaction: This explains clearly why in Lewis's modal realist scheme he needs counterparts instead of rigid designation. Sounds like a slippery slope. If you say 'Humphrey might have won the election', who are you talking about? |
| 21397 | Perception an open hand, a fist is 'grasping', and holding that fist is knowledge [Zeno of Citium, by Long] |
| Full Idea: Zeno said perceptions starts like an open hand; then the assent by our governing-principle is partly closing the hand; then full 'grasping' is like making a fist; and finally knowledge is grasping the fist with the other hand. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by A.A. Long - Hellenistic Philosophy 4.3.1 | |
| A reaction: [In Cicero, Acad 2.145] It sounds as if full knowledge requires meta-cognition - knowing that you know. |
| 20799 | A grasp by the senses is true, because it leaves nothing out, and so nature endorses it [Zeno of Citium, by Cicero] |
| Full Idea: He thought that a grasp made by the senses was true and reliable, …because it left out nothing about the object that could be grasped, and because nature had provided this grasp as a standard of knowledge, and a basis for understanding nature itself. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by M. Tullius Cicero - Academica I.42 | |
| A reaction: Sounds like Williamson's 'knowledge first' claim - that the basic epistemic state is knowledge, which we have when everything is working normally. I like Zeno's idea that a 'grasp' leaves nothing out about the object. Compare nature with Descartes' God. |
| 20797 | If a grasped perception cannot be shaken by argument, it is 'knowledge' [Zeno of Citium, by Cicero] |
| Full Idea: What had been grasped by sense-perception, he called this itself a 'sense-perception', and if it was grasped in such a way that it could not be shaken by argument he called it 'knowledge'. And between knowledge and ignorance he placed the 'grasp'. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by M. Tullius Cicero - Academica I.41 | |
| A reaction: This seems to say that a grasped perception is knowledge if there is no defeater. |
| 21398 | A presentation is true if we judge that no false presentation could appear like it [Zeno of Citium, by Cicero] |
| Full Idea: I possess a standard enabling me to judge presentations to be true when they have a character of a sort that false ones could not have. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by M. Tullius Cicero - Academica II.18.58 | |
| A reaction: [This is a spokesman in Cicero for the early Stoic view] No sceptic will accept this, but it is pretty much how I operate. If you see something weird, like a leopard wandering wild in Hampshire, you believe it once you have eliminated possible deceptions. |
| 10998 | The mind abstracts ways things might be, which are nonetheless real [Read] |
| Full Idea: Ways things might be are real, but only when abstracted from the actual way things are. They are brought out and distinguished by the mind, by abstraction, but are not dependent on mind for their existence. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) | |
| A reaction: To me this just flatly contradicts itself. The idea that the mind can 'bring something out' by its operations, with the result being then accepted as part of reality is nonsense on stilts. What is real is the powers that make the possibilities. |
| 1770 | When a slave said 'It was fated that I should steal', Zeno replied 'Yes, and that you should be beaten' [Zeno of Citium, by Diog. Laertius] |
| Full Idea: When a slave who was being beaten for theft said, 'It was fated that I should steal', Zeno replied, 'Yes, and that you should be beaten.' | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.Ze.19 |
| 3799 | A dog tied to a cart either chooses to follow and is pulled, or it is just pulled [Zeno of Citium, by Hippolytus] |
| Full Idea: Zeno and Chrysippus say everything is fated with the following model: when a dog is tied to a cart, if it wants to follow it is pulled and follows, making its spontaneous act coincide with necessity, but if it does not want to follow it will be compelled. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by Hippolytus - Refutation of All Heresies §1.21 | |
| A reaction: A nice example, but it is important to keep the distinction clear between freedom and free will. The dog lacks freedom as it is dragged along, but it is still free to will that it is asleep in its kennel. |
| 21402 | Incorporeal substances can't do anything, and can't be acted upon either [Zeno of Citium, by Cicero] |
| Full Idea: Zeno held that an incorporeal substance was incapable of any activity, whereas anything capable of acting, or being acted upon in any way, could not be incorporeal. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by M. Tullius Cicero - Academica I.11.39 | |
| A reaction: This is substance dualism kicked into the long grass by Zeno, long before Descartes defended dualism, and was swiftly met with exactly the same response. The interaction problem. |
| 20816 | A body is required for anything to have causal relations [Zeno of Citium, by Cicero] |
| Full Idea: Zeno held (contrary to Xenocrates and others) that it was impossible for anything to be effected that lacked a body, and indeed that whatever effected something or was affected by something must be body. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by M. Tullius Cicero - Academica I.39 | |
| A reaction: This seems to make stoics thoroughgoing physicalists, although they consider the mind to be made of refined fire, rather than of flesh. |
| 1773 | A sentence always has signification, but a word by itself never does [Zeno of Citium, by Diog. Laertius] |
| Full Idea: A sentence is always significative of something, but a word by itself has no signification. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.Ze.28 | |
| A reaction: This is the Fregean dogma. Words obviously can signify, but that is said to be parasitic on their use in sentences. It feels like a false dichotomy to me. Much sentence meaning is compositional. |
| 11005 | Negative existentials with compositionality make the whole sentence meaningless [Read] |
| Full Idea: A problem with compositionality is negative existential propositions. If some of the terms of the proposition are empty, and don't refer, then compositionality implies that the whole will lack meaning too. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.5) | |
| A reaction: I don't agree. I don't see why compositionality implies holism about sentence-meaning. If I say 'that circular square is a psychopath', you understand the predication, despite being puzzled by the singular term. |
| 10966 | A proposition objectifies what a sentence says, as indicative, with secure references [Read] |
| Full Idea: A proposition makes an object out of what is said or expressed by the utterance of a certain sort of sentence, namely, one in the indicative mood which makes sense and doesn't fail in its references. It can then be an object of thought and belief. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.1) | |
| A reaction: Nice, but two objections: I take it to be crucial to propositions that they eliminate ambiguities, and I take it that animals are capable of forming propositions. Read seems to regard them as fictions, but I take them to be brain events. |
| 13558 | The supreme good is harmony of spirit [Seneca] |
| Full Idea: The highest good is harmony of spirit. | |
| From: Seneca the Younger (On the Happy Life [c.60], §08) | |
| A reaction: This idea is straight from Plato's Republic. |
| 20841 | Zeno said live in agreement with nature, which accords with virtue [Zeno of Citium, by Diog. Laertius] |
| Full Idea: Zeno first (in his book On Human Nature) said that the goal was to live in agreement with nature, which is to live according to virtue. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.87 | |
| A reaction: The main idea seems to be Aristotelian - that the study of human nature reveals what our virtues are, and following them is what nature requires. Nature is taken to be profoundly rational. |
| 1774 | Since we are essentially rational animals, living according to reason is living according to nature [Zeno of Citium, by Diog. Laertius] |
| Full Idea: As reason is given to rational animals according to a more perfect principle, it follows that to live correctly according to reason, is properly predicated of those who live according to nature. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.Ze.52 | |
| A reaction: This is the key idea for understanding what the stoics meant by 'live according to nature'. The modern idea of rationality doesn't extend to 'perfect principles', however. |
| 20863 | The goal is to 'live in agreement', according to one rational consistent principle [Zeno of Citium, by Stobaeus] |
| Full Idea: Zeno says the goal of life is 'living in agreement', which means living according to a single and consonant rational principle, since those who live in conflict are unhappy. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by John Stobaeus - Anthology 2.06a | |
| A reaction: If there is a 'single' principle, is it possible to state it? To live by consistent principles sets the bar incredibly high, as any professional philosopher can tell you. |
| 2662 | Zeno saw virtue as a splendid state, not just a source of splendid action [Zeno of Citium, by Cicero] |
| Full Idea: Zeno held that not merely the exercise of virtue, as his predecessors held, but the mere state of virtue is in itself a splendid thing, although nobody possesses virtue without continuously exercising it. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by M. Tullius Cicero - Academica I.10.38 |
| 13559 | I seek virtue, because it is its own reward [Seneca] |
| Full Idea: You ask what I seek from virtue? Virtue herself. For she has nothing better, she is herself her own reward. | |
| From: Seneca the Younger (On the Happy Life [c.60], §09) | |
| A reaction: Presumably this is the source of the popular saying that 'virtue is its own reward'. The trouble is that this doesn't seem a very persuasive thing to say to a sceptic who doubts whether being virtuous is worth the trouble. |
| 21395 | One of Zeno's books was 'That Which is Appropriate' [Zeno of Citium, by Long] |
| Full Idea: Zeno of Citium wrote a (lost) book entitled 'That Which is Appropriate'. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by A.A. Long - Hellenistic Philosophy 4.1 | |
| A reaction: I cite this because I take it to be about what in Aristotle called 'the mean' - to emphasise that the mean is not what is average, or midway between the extremes, but what is a balanced response to each situation |
| 13561 | Virtue is always moderate, so excess need not be feared [Seneca] |
| Full Idea: In the case of virtue excess should not be feared, since in virtue resides moderation. | |
| From: Seneca the Younger (On the Happy Life [c.60], §13) | |
| A reaction: This seems to imply that all of the virtues are unified in the one achievement of the virtuous state. It leaves the notion of 'virtue' a bit thin in content, though. |
| 13562 | It is shameful to not even recognise your own slaves [Seneca] |
| Full Idea: Why, to your shame, are you so careless that you do not know your handful of slaves by sight? | |
| From: Seneca the Younger (On the Happy Life [c.60], §17) |
| 5964 | Zeno says there are four main virtues, which are inseparable but distinct [Zeno of Citium, by Plutarch] |
| Full Idea: Zeno (like Plato) admits a plurality of specifically different virtues, namely prudence, courage, sobriety, justice, which he takes to be inseparable but yet distinct and different from one another. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by Plutarch - 70: Stoic Self-contradictions 1034c | |
| A reaction: In fact, the virtues are 'supervenient' on one another, which is the doctrine of the unity of virtue. Zeno is not a pluralist in the way Aristotle is - who says there are other goods apart from the virtues. |
| 13564 | There is far more scope for virtue if you are wealthy; poverty only allows endurance [Seneca] |
| Full Idea: What doubt can there be that the wise man has greater scope for displaying his powers if he is rich than if he is poor, since in the case of poverty only one kind of virtue exists - refusal to be bowed down and crushed. | |
| From: Seneca the Younger (On the Happy Life [c.60], §22) | |
| A reaction: It is against this view that I see Jesus proposing poverty as central to virtue. But then he has the surprising view (to Seneca) that humility is a virtue. What Nietzsche calls the slaves' inversion of values. |
| 13563 | Why does your wife wear in her ears the income of a wealthy house? [Seneca] |
| Full Idea: Why does your wife wear in her ears the income of a wealthy house? | |
| From: Seneca the Younger (On the Happy Life [c.60], §17) |
| 13565 | If wealth was a good, it would make men good [Seneca] |
| Full Idea: Wealth is not a good; for it it was, it would make men good. | |
| From: Seneca the Younger (On the Happy Life [c.60], §24) | |
| A reaction: An immediately attractive argument, but should we assume that anything which is good will enhance our personal goodness? If goodness is a habit, then continual pursuit of wealth is the test case to examine. Seneca is right! |
| 13557 | Unfortunately the majority do not tend to favour what is best [Seneca] |
| Full Idea: Human concerns are not so happily arranged that the majority favours the better things. | |
| From: Seneca the Younger (On the Happy Life [c.60], §02) | |
| A reaction: On the whole Seneca is unimpressed by democracy, as people are rushed into decisions by the crowd, and live to regret them. |
| 20822 | There is no void in the cosmos, but indefinite void outside it [Zeno of Citium, by Ps-Plutarch] |
| Full Idea: Zeno and his followers say that there is no void within the cosmos but an indefinite void outside it. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by Pseudo-Plutarch - On the Doctrine of the Philosophers 884a | |
| A reaction: Only atomists (such as Epicureans) need void within the cosmos, as space within which atoms can move. What would they make of modern 'fields'? Posidonius later said there was sufficient, but not infinite, void. |
| 2648 | Things are more perfect if they have reason; nothing is more perfect than the universe, so it must have reason [Zeno of Citium] |
| Full Idea: That which has reason is more perfect than that which has not. But there is nothing more perfect than the universe; therefore the universe is a rational being. | |
| From: Zeno (Citium) (fragments/reports [c.294 BCE]), quoted by M. Tullius Cicero - On the Nature of the Gods ('De natura deorum') II.20 |
| 20811 | Since the cosmos produces what is alive and rational, it too must be alive and rational [Zeno of Citium] |
| Full Idea: Nothing which lacks life and reason can produce from itself something which is alive and rational; but the cosmos can produce from itself things which are alive and rational; therefore the cosmos is alive and rational. | |
| From: Zeno (Citium) (fragments/reports [c.294 BCE]), quoted by M. Tullius Cicero - On the Nature of the Gods ('De natura deorum') 2.22 | |
| A reaction: Eggs and sperm don't seem to be rational, but I don't suppose they count. I note that this is presented as a formal proof, when actually it is just an evaluation of evidence. Logic as rhetoric, I would say. |
| 20810 | Rational is better than non-rational; the cosmos is supreme, so it is rational [Zeno of Citium] |
| Full Idea: That which is rational is better than that which is not rational; but there is nothing better than the cosmos; therefore, the cosmos is rational. | |
| From: Zeno (Citium) (fragments/reports [c.294 BCE]), quoted by M. Tullius Cicero - On the Nature of the Gods ('De natura deorum') 2.21 | |
| A reaction: This looks awfully like Anselm's ontological argument to me. The cosmos was the greatest thing that Zeno could conceive. |
| 2649 | If tuneful flutes grew on olive trees, you would assume the olive had some knowledge of the flute [Zeno of Citium] |
| Full Idea: If flutes playing tunes were to grow on olive trees, would you not infer that the olive must have some knowledge of the flute? | |
| From: Zeno (Citium) (fragments/reports [c.294 BCE]), quoted by M. Tullius Cicero - On the Nature of the Gods ('De natura deorum') II.22 |
| 20807 | The cosmos and heavens are the substance of god [Zeno of Citium, by Diog. Laertius] |
| Full Idea: Zeno says that the entire cosmos and the heaven are the substance of god. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.148 |