97 ideas
| 13689 | 'Theorems' are formulas provable from no premises at all [Sider] |
| Full Idea: Formulas provable from no premises at all are often called 'theorems'. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.6) |
| 13705 | Truth tables assume truth functionality, and are just pictures of truth functions [Sider] |
| Full Idea: The method of truth tables assumes truth functionality. Truth tables are just pictures of truth functions. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.3) |
| 13706 | Intuitively, deontic accessibility seems not to be reflexive, but to be serial [Sider] |
| Full Idea: Deontic accessibility seems not to be reflexive (that it ought to be true doesn't make it true). One could argue that it is serial (that there is always a world where something is acceptable). | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.3.1) |
| 13710 | In D we add that 'what is necessary is possible'; then tautologies are possible, and contradictions not necessary [Sider] |
| Full Idea: In D we add to K a new axiom saying that 'what's necessary is possible' (□φ→◊φ), ..and it can then be proved that tautologies are possible and contradictions are not necessary. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.4.2) |
| 13711 | System B introduces iterated modalities [Sider] |
| Full Idea: With system B we begin to be able to say something about iterated modalities. ..S4 then takes a different stand on the iterated modalities, and neither is an extension of the other. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.4.4) |
| 13708 | S5 is the strongest system, since it has the most valid formulas, because it is easy to be S5-valid [Sider] |
| Full Idea: S5 is the strongest system, since it has the most valid formulas. That's because it has the fewest models; it's easy to be S5-valid since there are so few potentially falsifying models. K is the weakest system, for opposite reasons. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.3.2) | |
| A reaction: Interestingly, the orthodox view is that S5 is the correct logic for metaphysics, but it sounds a bit lax. Compare Idea 13707. |
| 13712 | Epistemic accessibility is reflexive, and allows positive and negative introspection (KK and K¬K) [Sider] |
| Full Idea: Epistemic accessibility should be required to be reflexive (allowing Kφ→φ). S4 allows the 'KK principle', or 'positive introspection' (Kφ→KKφ), and S5 allows 'negative introspection' (¬Kφ→K¬Kφ). | |
| From: Theodore Sider (Logic for Philosophy [2010], 7.2) |
| 13714 | We can treat modal worlds as different times [Sider] |
| Full Idea: We can think of the worlds of modal logic as being times, rather than 'possible' worlds. | |
| From: Theodore Sider (Logic for Philosophy [2010], 7.3.3) |
| 13720 | Converse Barcan Formula: □∀αφ→∀α□φ [Sider] |
| Full Idea: The Converse Barcan Formula reads □∀αφ→∀α□φ (or an equivalent using ◊). | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.5.2) | |
| A reaction: I would read that as 'if all the αs happen to be φ, then αs have to be φ'. Put like that, I would have thought that it was obviously false. Sider points out that some new object could turn up which isn't φ. |
| 13718 | The Barcan Formula ∀x□Fx→□∀xFx may be a defect in modal logic [Sider] |
| Full Idea: The Barcan Formula ∀x□Fx→□∀xFx is often regarded as a defect of Simple Quantified Modal Logic, though this most clearly seen in its equivalent form ◊∃xFx→∃x◊Fx. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.5.2) | |
| A reaction: [See Idea 13719 for an explanation why it might be a defect] I translate the first one as 'if xs must be F, then they are always F', and the second one as 'for x to be possibly F, there must exist an x which is possibly F'. Modality needs existence. |
| 13723 | System B is needed to prove the Barcan Formula [Sider] |
| Full Idea: The proof of the Barcan Formula require System B. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.7) |
| 13715 | You can employ intuitionist logic without intuitionism about mathematics [Sider] |
| Full Idea: Not everyone who employs intuitionistic logic is an intuitionist about mathematics. | |
| From: Theodore Sider (Logic for Philosophy [2010], 7.4.1) | |
| A reaction: This seems worthy of note, since it may be tempting to reject the logic because of the implausibility of the philosophy of mathematics. I must take intuitionist logic more seriously. |
| 13678 | The most popular account of logical consequence is the semantic or model-theoretic one [Sider] |
| Full Idea: On the question of the nature of genuine logical consequence, ...the most popular answer is the semantic, or model-theoretic one. | |
| From: Theodore Sider (Logic for Philosophy [2010], 1.5) | |
| A reaction: Reading the literature, one might be tempted to think that this is the only account that anyone takes seriously. Substitutional semantics seems an interesting alternative. |
| 13679 | Maybe logical consequence is more a matter of provability than of truth-preservation [Sider] |
| Full Idea: Another answer to the question about the nature of logical consequence is a proof-theoretic one, according to which it is more a matter of provability than of truth-preservation. | |
| From: Theodore Sider (Logic for Philosophy [2010], 1.5) | |
| A reaction: I don't like this, and prefer the model-theoretic or substitutional accounts. Whether you can prove that something is a logical consequence seems to me entirely separate from whether you can see that it is so. Gödel seems to agree. |
| 13682 | Maybe logical consequence is impossibility of the premises being true and the consequent false [Sider] |
| Full Idea: The 'modal' account of logical consequence is that it is not possible for the premises to be true and the consequent false (under some suitable notion of possibility). | |
| From: Theodore Sider (Logic for Philosophy [2010], 1.5) | |
| A reaction: Sider gives a nice summary of five views of logical consequence, to which Shapiro adds substitutional semantics. |
| 13680 | Maybe logical consequence is a primitive notion [Sider] |
| Full Idea: There is a 'primitivist' account, according to which logical consequence is a primitive notion. | |
| From: Theodore Sider (Logic for Philosophy [2010], 1.5) | |
| A reaction: While sympathetic to substitutional views (Idea 13674), the suggestion here pushes me towards thinking that truth must be at the root of it. The trouble, though, is that a falsehood can be a good logical consequence of other falsehoods. |
| 13722 | A 'theorem' is an axiom, or the last line of a legitimate proof [Sider] |
| Full Idea: A 'theorem' is defined as the last line of a proof in which each line is either an axiom or follows from earlier lines by a rule. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.7) | |
| A reaction: In other words, theorems are the axioms and their implications. |
| 13696 | When a variable is 'free' of the quantifier, the result seems incapable of truth or falsity [Sider] |
| Full Idea: When a variable is not combined with a quantifier (and so is 'free'), the result is, intuitively, semantically incomplete, and incapable of truth or falsity. | |
| From: Theodore Sider (Logic for Philosophy [2010], 4.2) |
| 13700 | A 'total' function must always produce an output for a given domain [Sider] |
| Full Idea: Calling a function a 'total' function 'over D' means that the function must have a well-defined output (which is a member of D) whenever it is given as inputs any n members of D. | |
| From: Theodore Sider (Logic for Philosophy [2010], 5.2) |
| 13703 | λ can treat 'is cold and hungry' as a single predicate [Sider] |
| Full Idea: We might prefer λx(Fx∧Gx)(a) as the symbolization of 'John is cold and hungry', since it treats 'is cold and hungry' as a single predicate. | |
| From: Theodore Sider (Logic for Philosophy [2010], 5.5) |
| 13688 | Good axioms should be indisputable logical truths [Sider] |
| Full Idea: Since they are the foundations on which a proof rests, the axioms in a good axiomatic system ought to represent indisputable logical truths. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.6) |
| 13687 | No assumptions in axiomatic proofs, so no conditional proof or reductio [Sider] |
| Full Idea: Axiomatic systems do not allow reasoning with assumptions, and therefore do not allow conditional proof or reductio ad absurdum. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.6) | |
| A reaction: Since these are two of the most basic techniques of proof which I have learned (in Lemmon), I shall avoid axiomatic proof systems at all costs, despites their foundational and Ockhamist appeal. |
| 13690 | Proof by induction 'on the length of the formula' deconstructs a formula into its accepted atoms [Sider] |
| Full Idea: The style of proof called 'induction on formula construction' (or 'on the number of connectives', or 'on the length of the formula') rest on the fact that all formulas are built up from atomic formulas according to strict rules. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.7) | |
| A reaction: Hence the proof deconstructs the formula, and takes it back to a set of atomic formulas have already been established. |
| 13691 | Induction has a 'base case', then an 'inductive hypothesis', and then the 'inductive step' [Sider] |
| Full Idea: A proof by induction starts with a 'base case', usually that an atomic formula has some property. It then assumes an 'inductive hypothesis', that the property is true up to a certain case. The 'inductive step' then says it will be true for the next case. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.7) | |
| A reaction: [compressed] |
| 13685 | Natural deduction helpfully allows reasoning with assumptions [Sider] |
| Full Idea: The method of natural deduction is popular in introductory textbooks since it allows reasoning with assumptions. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.5) | |
| A reaction: Reasoning with assumptions is generally easier, rather than being narrowly confined to a few tricky axioms, You gradually show that an inference holds whatever the assumption was, and so end up with the same result. |
| 13686 | We can build proofs just from conclusions, rather than from plain formulae [Sider] |
| Full Idea: We can construct proofs not out of well-formed formulae ('wffs'), but out of sequents, which are some premises followed by their logical consequence. We explicitly keep track of the assumptions upon which the conclusion depends. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.5.1) | |
| A reaction: He says the method of sequents was invented by Gerhard Gentzen (the great nazi logician) in 1935. The typical starting sequents are the introduction and elimination rules. E.J. Lemmon's book, used in this database, is an example. |
| 13697 | Valuations in PC assign truth values to formulas relative to variable assignments [Sider] |
| Full Idea: A valuation function in predicate logic will assign truth values to formulas relative to variable assignments. | |
| From: Theodore Sider (Logic for Philosophy [2010], 4.2) | |
| A reaction: Sider observes that this is a 'double' relativisation (due to Tarski), since propositional logic truth was already relative to an interpretation. Now we are relative to variable assignments as well. |
| 13684 | The semantical notion of a logical truth is validity, being true in all interpretations [Sider] |
| Full Idea: The semantical notion of a logical truth is that of a valid formula, which is true in all interpretations. In propositional logic they are 'tautologies'. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.3) | |
| A reaction: This implies that there is a proof-theoretic account of logical truth as well. Intuitively a logical truth is a sequent which holds no matter which subject matter it refers to, so the semantic view sounds OK. |
| 13704 | It is hard to say which are the logical truths in modal logic, especially for iterated modal operators [Sider] |
| Full Idea: It isn't clear which formulas of modal propositional logic are logical truths, ...especially for sentences that contain iterations of modal operators. Is □P→□□P a logical truth? It's hard to say. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.3) | |
| A reaction: The result, of course, is that there are numerous 'systems' for modal logic, so that you can choose the one that gives you the logical truths you want. His example is valid in S4 and S5, but not in the others. |
| 13724 | In model theory, first define truth, then validity as truth in all models, and consequence as truth-preservation [Sider] |
| Full Idea: In model theory one normally defines some notion of truth in a model, and then uses it to define validity as truth in all models, and semantic consequence as the preservation of truth in models. | |
| From: Theodore Sider (Logic for Philosophy [2010], 10.1) |
| 13698 | In a complete logic you can avoid axiomatic proofs, by using models to show consequences [Sider] |
| Full Idea: You can establish facts of the form Γ|-φ while avoiding the agonies of axiomatic proofs by reasoning directly about models to conclusions about semantic consequence, and then citing completeness. | |
| From: Theodore Sider (Logic for Philosophy [2010], 4.5) | |
| A reaction: You cite completeness by saying that anything which you have shown to be a semantic consequence must therefore be provable (in some way). |
| 13699 | Compactness surprisingly says that no contradictions can emerge when the set goes infinite [Sider] |
| Full Idea: Compactness is intuitively surprising, ..because one might have thought there could be some contradiction latent within some infinite set, preventing it from being satisfiable, only discovered when you consider the whole set. But this can't happen. | |
| From: Theodore Sider (Logic for Philosophy [2010], 4.5) |
| 13701 | A single second-order sentence validates all of arithmetic - but this can't be proved axiomatically [Sider] |
| Full Idea: A single second-order sentence has second-order semantic consequences which are all and only the truths of arithmetic, but this is cold comfort because of incompleteness; no axiomatic system draws out the consequences of this axiom. | |
| From: Theodore Sider (Logic for Philosophy [2010], 5.4.3) |
| 13692 | A 'precisification' of a trivalent interpretation reduces it to a bivalent interpretation [Sider] |
| Full Idea: For a 'precisification' we take a trivalent interpretation and preserve the T and F values, and then assign all the third values in some way to either T or F. | |
| From: Theodore Sider (Logic for Philosophy [2010], 3.4.5) | |
| A reaction: [my informal summary of Sider's formal definition] |
| 13695 | Supervaluational logic is classical, except when it adds the 'Definitely' operator [Sider] |
| Full Idea: Supervaluation preserves classical logic (even though supervaluations are three-valued), except when we add the Δ operator (meaning 'definitely' or 'determinately'). | |
| From: Theodore Sider (Logic for Philosophy [2010], 3.4.5) |
| 13693 | A 'supervaluation' assigns further Ts and Fs, if they have been assigned in every precisification [Sider] |
| Full Idea: In a 'supervaluation' we take a trivalent interpretation, and assign to each wff T (or F) if it is T (or F) in every precisification, leaving the third truth-value in any other cases. The wffs are then 'supertrue' or 'superfalse' in the interpretation. | |
| From: Theodore Sider (Logic for Philosophy [2010], 3.4.5) | |
| A reaction: [my non-symbolic summary] Sider says the Ts and Fs in the precisifications are assigned 'in any way you like', so supervaluation is a purely formal idea, not a technique for eliminating vagueness. |
| 13694 | We can 'sharpen' vague terms, and then define truth as true-on-all-sharpenings [Sider] |
| Full Idea: We can introduce 'sharpenings', to make vague terms precise without disturbing their semantics. Then truth (or falsity) becomes true(false)-in-all-sharpenings. You are only 'rich' if you are rich-on-all-sharpenings of the word. | |
| From: Theodore Sider (Logic for Philosophy [2010], 3.4.5) | |
| A reaction: Not very helpful. Lots of people might be considered rich in many contexts, but very few people would be considered rich in all contexts. You are still left with some vague middle ground. |
| 13683 | A relation is a feature of multiple objects taken together [Sider] |
| Full Idea: A relation is just a feature of multiple objects taken together. | |
| From: Theodore Sider (Logic for Philosophy [2010], 1.8) | |
| A reaction: Appealingly simple, especially for a logician, who can then just list the relevant objects as members of a set, and the job is done. But if everyone to the left of me is also taller than me, this won't quite do. |
| 13702 | The identity of indiscernibles is necessarily true, if being a member of some set counts as a property [Sider] |
| Full Idea: The identity of indiscernibles (∀x∀y(∀X(Xx↔Xy)→x=y) is necessarily true, provided that we construe 'property' very broadly, so that 'being a member of such-and-such set' counts as a property. | |
| From: Theodore Sider (Logic for Philosophy [2010], 5.4.3) | |
| A reaction: Sider's example is that if the two objects are the same they must both have the property of being a member of the same singleton set, which they couldn't have if they were different. |
| 13721 | 'Strong' necessity in all possible worlds; 'weak' necessity in the worlds where the relevant objects exist [Sider] |
| Full Idea: 'Strong necessity' requires the truth of 'necessarily φ' is all possible worlds. 'Weak necessity' merely requires that 'necessarily φ' be true in all worlds in which objects referred to within φ exist. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.6.3) | |
| A reaction: This seems to be a highly desirably distinction, given the problem of Idea 13719. It is weakly necessary that humans can't fly unaided, assuming we are referring the current feeble wingless species. That hardly seems to be strongly necessary. |
| 13707 | Maybe metaphysical accessibility is intransitive, if a world in which I am a frog is impossible [Sider] |
| Full Idea: Some argue that metaphysical accessibility is intransitive. The individuals involved mustn't be too different from the actual world. A world in which I am a frog isn't metaphysically possible. Perhaps the logic is modal system B or T. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.3.1) | |
| A reaction: This sounds rather plausible and attractive to me. We don't want to say that I am necessarily the way I actually am, though, so we need criteria. Essence! |
| 13709 | Logical truths must be necessary if anything is [Sider] |
| Full Idea: On any sense of necessity, surely logical truths must be necessary. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.4) |
| 13716 | 'If B hadn't shot L someone else would have' if false; 'If B didn't shoot L, someone else did' is true [Sider] |
| Full Idea: To show the semantic difference between counterfactuals and indicative conditionals, 'If Booth hadn't shot Lincoln someone else would have' is false, but 'If Booth didn't shoot Lincoln then someone else did' is true. | |
| From: Theodore Sider (Logic for Philosophy [2010], 8) | |
| A reaction: He notes that indicative conditionals also differ in semantics from material and strict conditionals. The first example allows a world where Lincoln was not shot, but the second assumes our own world, where he was. Contextual domains? |
| 13717 | Transworld identity is not a problem in de dicto sentences, which needn't identify an individual [Sider] |
| Full Idea: There is no problem of transworld identification with de dicto modal sentence, for their evaluation does not require taking an individual from one possible world and reidentifying it in another. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.2) | |
| A reaction: If 'de dicto' is about the sentence and 'de re' is about the object (Idea 5732), how do you evaluate the sentence without at least some notion of the object to which it refers. Nec the Prime Minister chairs the cabinet. Could a poached egg do the job? |
| 13719 | Barcan Formula problem: there might have been a ghost, despite nothing existing which could be a ghost [Sider] |
| Full Idea: A problem with the Barcan Formula is it might be possible for there to exist a ghost, even though there in fact exists nothing that could be a ghost. There could have existed some 'extra' thing which could be a ghost. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.5.2) | |
| A reaction: Thus when we make modal claims, do they only refer to what actually exists, or is specified in our initial domain? Can a claim enlarge the domain? Are domains 'variable'? Simple claims about what might have existed seem to be a problem. |
| 19906 | All countries are in a mutual state of nature [Locke] |
| Full Idea: All commonwealths are in a state of Nature one with another. | |
| From: John Locke (Second Treatise of Government [1690], 153) | |
| A reaction: A striking remark. It is easy to think that the state of nature no longer exists. International law attempts to rectify this, but diplomacy is much more like negotiations in nature than it is like obedience to laws. |
| 19882 | We are not created for solitude, but are driven into society by our needs [Locke] |
| Full Idea: God, having made man such a creature that, in His own judgement, it was not good for him to be alone, put him under strong obligations of necessity, convenience, and inclination, to drive him into society. | |
| From: John Locke (Second Treatise of Government [1690], 077) | |
| A reaction: This is almost Aristotelian, apart from the individualistic assumption that we are 'driven' into society. The only time I see other people looking generally happy is when they are sitting around at leisure and talking to other people. |
| 19864 | In nature men can dispose of possessions and their persons in any way that is possible [Locke] |
| Full Idea: The estate all men are naturally in is perfect freedom to order their actions, and dispose of their possessions and persons as they think fit, within the bounds of the laws of nature. | |
| From: John Locke (Second Treatise of Government [1690], 004) | |
| A reaction: Note that they have possessions, so property is not an invention of society, but something which society should protect. Presumably Locke thinks they could sell themselves into slavery, which Rousseau rejects. |
| 19865 | There is no subjection in nature, and all creatures of the same species are equal [Locke] |
| Full Idea: Creatures of the same species and rank, promiscuously born to all the same advantages of Nature, are also equal one among another, without subordination or subjection. | |
| From: John Locke (Second Treatise of Government [1690], 004) | |
| A reaction: The birds in my garden don't behave as if that were true. Physical strength is surely a natural inequality. |
| 19866 | The rational law of nature says we are all equal and independent, and should show mutual respect [Locke] |
| Full Idea: The state of Nature has a law of Nature to govern it, which obliges everyone, and reason, which is that law, teaches mankind that all being equal and independent, no one ought to harm another in his life, health, liberty or possessions. | |
| From: John Locke (Second Treatise of Government [1690], 006) | |
| A reaction: He adds that this is because we are all the property of God. Locke is more optimistic than Hobbes or Rousseau about this, since he thinks we have a natural obligation to be nice. |
| 19872 | The animals and fruits of the earth belong to mankind [Locke] |
| Full Idea: All the fruits the earth naturally produces, and beasts it feeds, belong to mankind in common, as they are produced by the spontaneous hand of Nature. | |
| From: John Locke (Second Treatise of Government [1690], 026) | |
| A reaction: Not a popular view among 21st century ecologists, I guess, but this remains the implicit belief of anyone who goes hunting in the woods, and our enclosed gardens seem to endorse the idea. |
| 19907 | There is a natural right to inheritance within a family [Locke] |
| Full Idea: Every man is born with a right before any other man, to inherit, with his brethren, his father's goods. | |
| From: John Locke (Second Treatise of Government [1690], 190) | |
| A reaction: If a child is fully grown, they may well have drifted into a state of partial ownership of the goods of the parent, of which it would be hard then to deprive them. It is hard to see this as a natural right of tiny orphaned infants. |
| 19863 | Politics is the right to make enforceable laws to protect property and the state, for the common good [Locke] |
| Full Idea: Political power is the right of making laws, with penalties up to death, for the preserving of property, employing the force of community in the execution of such laws, in defence of the commonwealth, and only for the common good. | |
| From: John Locke (Second Treatise of Government [1690], 003) | |
| A reaction: Since political power can be used for selfish corruption and genocide, this isn't very accurate, so I take it this is how power ought to be exercised! Notice that defence gets equal billing with his famous defence of property. |
| 5654 | The Second Treatise explores the consequences of the contractual view of the state [Locke, by Scruton] |
| Full Idea: In his second Treatise, Locke gave us perhaps the first extended account of the true logical consequences of Hobbes's contractual view of the state. | |
| From: report of John Locke (Second Treatise of Government [1690]) by Roger Scruton - Short History of Modern Philosophy Ch.14 | |
| A reaction: The issue seems to boil down to an opposition between the Cartesian and the Aristotelian view of the individual, with Locke following Descartes. The alternative, endorsed by Hegel, which I prefer, is that the state is part of human nature. |
| 19888 | A society only begins if there is consent of all the individuals to join it [Locke] |
| Full Idea: The beginning of politic society depends upon the consent of the individuals to join into and make one society. | |
| From: John Locke (Second Treatise of Government [1690], 106) | |
| A reaction: This is the dramatic new political idea (originating with Hobbes), that all of the members must (at some point) consent to the state. In practice we are all born into a state, so it is not clear what this means in real life. |
| 6702 | If anyone enjoys the benefits of government (even using a road) they give tacit assent to its laws [Locke] |
| Full Idea: Every man, that hath an possession, or enjoyment, of any part of the dominions of any government, doth thereby give his tacit consent, and is obliged to obedience to the laws, ..whether it be barely travelling on the highway. | |
| From: John Locke (Second Treatise of Government [1690], 119), quoted by Gordon Graham - Eight Theories of Ethics Ch.8 | |
| A reaction: Locke's famous assertion of an unspoken and inescapable contract, to which we are all subject. Hume gave an effective reply (Idea 6703). Locke has a point though. The more you accept, the more obliged you are. I accept the law more as I get older. |
| 19909 | A politic society is created from a state of nature by a unanimous agreement [Locke] |
| Full Idea: That which makes the community, and brings men out of the loose state of Nature into one politic society, is the agreement that everyone has with the rest to incorporate and act as one body. | |
| From: John Locke (Second Treatise of Government [1690], 211) | |
| A reaction: Geography usually keeps commonwealths in place once they have been established, but some of them become disfunctional hell holes because they are trapped in perpetual disagreement. |
| 19910 | A single will creates the legislature, which is duty-bound to preserve that will [Locke] |
| Full Idea: The essence and union of the society consisting in having one will; the legislative, when once established by the majority, has the declaring and, as it were, keeping of that will. | |
| From: John Locke (Second Treatise of Government [1690], 212) | |
| A reaction: Not far from Rousseau's big idea, apart from the emphasis on the 'majority'. Rousseau reduced the role of the general will to preliminaries and basics, but wanted close to unanimity, so that everyone accepts being a subject, to government and law. |
| 19893 | Anyone who enjoys the benefits of a state has given tacit consent to be part of it [Locke] |
| Full Idea: Every man that hath any possession or enjoyment of any part of the dominions of any government doth thereby give his tacit consent, and is as far forth obliged to obedience to the laws of that government, during such enjoyment. | |
| From: John Locke (Second Treatise of Government [1690], 119) | |
| A reaction: I wondered at the age of about 18 whether I had given tacit consent to be a British citizen. Locke says you only have to travel freely down the highways to give consent! We are all free, of course, to apply for citizenship elsewhere. But Idea 19894. |
| 19894 | You can only become an actual member of a commonwealth by an express promise [Locke] |
| Full Idea: Nothing can make any man a subject or member of a commonwealth but his actually entering into it by positive engagement, and express promise and compact. | |
| From: John Locke (Second Treatise of Government [1690], 122) | |
| A reaction: In practice the indigenous population never do this. But it a clear distinction for foreign residents in any country. States cannot induct resident foreigners into their army, or allow them to vote. |
| 19892 | Children are not born into citizenship of a state [Locke] |
| Full Idea: It is plain, by the practices of governments themselves, as well as by the laws of right reason, that a child is born a subject of no country nor government. | |
| From: John Locke (Second Treatise of Government [1690], 118) | |
| A reaction: At what age do they become citizens, given that there is no induction ceremony? If a small British child were attacked overseas, we would expect the British government to defend its rights. |
| 19885 | Absolute monarchy is inconsistent with civil society [Locke] |
| Full Idea: Absolute monarchy, which by some men is counted for the only government in the world, is inconsistent with civil society, and so can be no form of civil government at all. | |
| From: John Locke (Second Treatise of Government [1690], 090) | |
| A reaction: This is because citizens do not have a 'decisive' power to appeal for redress of injuries. Rousseau thought that there could be an absolute monarchy, as long as the general will agreed it, and its term of office could be brought to an end by the assembly. |
| 19886 | The idea that absolute power improves mankind is confuted by history [Locke] |
| Full Idea: He that thinks absolute power purifies men's blood, and corrects the baseness of human nature, need but read the history of this, or any other age, to be convinced to the contrary. | |
| From: John Locke (Second Treatise of Government [1690], 092) | |
| A reaction: I can't imagine who proposed the view that Locke is attacking, but it will have been some real 17th century thinker. Attitudes to monarchy changed drastically in England, but Louis XIV was still ruling in France. |
| 19903 | Despotism is arbitrary power to kill, based neither on natural equality, nor any social contract [Locke] |
| Full Idea: Despotical power is an absolute, arbitrary power one man over another, to take away his life whenever he pleases; and this is a power which neither Nature gives, for it has made no such distinction between one man and another, nor compact can convey. | |
| From: John Locke (Second Treatise of Government [1690], 172) | |
| A reaction: Colonies of seals, walruses and apes seem to display despotism, based on physical strength, though that is largely to do with mating. There could be such a compact, but Locke would regard it as invalid. |
| 19905 | People stripped of their property are legitimately subject to despotism [Locke] |
| Full Idea: Forfeiture gives despotical power to lords for their own benefit over those who are stripped of all property. ...Despotical power is over such as have no property at all. | |
| From: John Locke (Second Treatise of Government [1690], 173) | |
| A reaction: Nasty! Shylock is stripped of his property by Venice, so these things happened. This is taking the significance of property a long way beyond its role at the beginning of Locke's book. Property is the start of society, but then becomes your passport. |
| 19904 | Legitimate prisoners of war are subject to despotism, because that continues the state of war [Locke] |
| Full Idea: Captives, taken in a just and lawful war, and such only, are subject to a despotical power, which, as it arises not from compact, so neither is it capable of any, but is the state of war continued. | |
| From: John Locke (Second Treatise of Government [1690], 205) | |
| A reaction: How long after a war finishes is such despotism legitimate? What happened to the German prisoners in Russia in 1945? Locke defined despotism as the right to kill, but that is expressly contrary to the rules of war, look you. |
| 19895 | Even the legislature must be preceded by a law which gives it power to make laws [Locke] |
| Full Idea: The first and fundamental positive law of all commonwealths is the establishing of the legislative power, as the first and fundamental natural law which is to govern even the legislative. | |
| From: John Locke (Second Treatise of Government [1690], 134) | |
| A reaction: I think Rousseau says that there cannot be a law which enables the general will to set up legislative powers. It just seems to be something which happens. Locke is threatened with an infinite regress. What legitimises the enabling law? |
| 19900 | The executive must not be the legislature, or they may exempt themselves from laws [Locke] |
| Full Idea: It may be too great temptation to human frailty, apt to grasp at power, for the same persons to have the power of making laws to also have in their hands the power to execute them, whereby they may exempt themselves. | |
| From: John Locke (Second Treatise of Government [1690], 143) | |
| A reaction: The main principles of modern constitutions are devised to avoid corruption. If people were incorruptible (yeah, right) the world would presumably be run very differently, and rather more efficiently, like a good family. |
| 19902 | Any obstruction to the operation of the legislature can be removed forcibly by the people [Locke] |
| Full Idea: Having erect a legislative with the power of making laws, when they are hindered by any force from what is so necessary to society, and wherein the safety and preservation of the people consists, the people have a right to remove it by force. | |
| From: John Locke (Second Treatise of Government [1690], 155) | |
| A reaction: I doubt if he was thinking of the French Revolution, but this will clearly have application to the English events of 1642. The Speaker of the Commons was held down in his chair in the 1620s, so that some legislation could be enacted. |
| 19908 | Rebelling against an illegitimate power is no sin [Locke] |
| Full Idea: It is plain that shaking off a power which force, and not right, hath set over any one, though it have the name of rebellion, yet it is no offence against God. | |
| From: John Locke (Second Treatise of Government [1690], 196) | |
| A reaction: [He cites Hezekiah at 2 Kings 18.7] At this time the English Civil War was referred to as the 'Great Rebellion' (so this is an interesting and brave remark of Locke's), though few people would think that Charles I had illegitimate power. |
| 19911 | If legislators confiscate property, or enslave people, they are no longer owed obedience [Locke] |
| Full Idea: Whenever the legislators endeavour to take away and destroy the property of the people, or reduce them to slavery under arbitrary power, they put themselves into a state of war with the people, who are thereupon absolved from any further obedience. | |
| From: John Locke (Second Treatise of Government [1690], 222) | |
| A reaction: This might fit Louis XVI in 1788. Locke was certainly not averse to consideration the situations in which revolution might be justified. He was trying to be even-handed about 1642. Locke seems to think that without property you ARE a slave. |
| 19901 | The people have supreme power, to depose a legislature which has breached their trust [Locke] |
| Full Idea: There remains still in the people a supreme power to remove or alter the legislative, when they find the legislative act contrary to the trust reposed in them. | |
| From: John Locke (Second Treatise of Government [1690], 149) | |
| A reaction: This seems to be the most important aspect of representative democracy. It is not the power of people to make decisions, but the power to get rid of bad rulers. |
| 19887 | Unanimous consent makes a united community, which is then ruled by the majority [Locke] |
| Full Idea: When any number of men have, by the consent of every individual, made a community, they have thereby made that community into one body, with a power to act as one body, which is only by the will and determination of the majority. | |
| From: John Locke (Second Treatise of Government [1690], 096) | |
| A reaction: This seems to be presume democracy without discussion, although the formation of the community is by universal consent, which is the 'general will'. Rousseau has the constitution also made almost unanimously, not by a majority. |
| 19913 | A master forfeits ownership of slaves he abandons [Locke] |
| Full Idea: A master forfeits the dominion over his slaves whom he hath abandoned. | |
| From: John Locke (Second Treatise of Government [1690], 237) | |
| A reaction: How often did slave owners take a day off, I wonder? Presumably slaves will take back their freedom, even if the masters haven't 'forfeited' their ownership, so Locke's point is fairly academic. |
| 19883 | Slaves captured in a just war have no right to property, so are not part of civil society [Locke] |
| Full Idea: Slave are captives taken in a just war, and by right of Nature subjected to the absolute dominion and arbitrary power of their masters. ...Being not capable of any property, they cannot in that state be considered any part of civil society. | |
| From: John Locke (Second Treatise of Government [1690], 085) | |
| A reaction: If the test of citizenship is being capable of holding property, presumably children and mentally damaged people (including the very old) will also fail to qualify. I see no principled reason why slaves should not be allowed to vote. Note 'just' war. |
| 19870 | If you try to enslave me, you have declared war on me [Locke] |
| Full Idea: He who makes an attempt to enslave me thereby puts himself into a state of war with me. | |
| From: John Locke (Second Treatise of Government [1690], 017) | |
| A reaction: So presumably actual slaves are in a state of permanent war with their owners. What of a woman who is enslaved by her husband? |
| 19871 | Freedom is not absence of laws, but living under laws arrived at by consent [Locke] |
| Full Idea: Liberty of man in society is to be under no other legislative power but that established by consent in the commonwealth. Freedom is not (as Filmer suggests) doing what you please while not tied by any laws. | |
| From: John Locke (Second Treatise of Government [1690], 022) | |
| A reaction: That sounds plausible if the consent is unanimous, but a minority is not free if the laws made by a large majority are a sort of persecution. |
| 19880 | All value depends on the labour involved [Locke] |
| Full Idea: It is labour that puts the difference of value on everything. ...Whatever bread is worth more than acorns, wine than water, that is wholly owing to labour and industry. | |
| From: John Locke (Second Treatise of Government [1690], 040) | |
| A reaction: In capitalism this is nonsense. Supply and demand fix all the values. Locke has slid from labour bestowing ownership to labour bestowing value. No one gets paid on the basis of how hard they work, except on piece rates. |
| 19873 | We all own our bodies, and the work we do is our own [Locke] |
| Full Idea: Every man has a 'property' in his own 'person'. This nobody has any right to it but himself. The 'labour' of his body and the 'work' of his hands, we may say, are properly his. | |
| From: John Locke (Second Treatise of Government [1690], 027) | |
| A reaction: He doesn't have any grounds for this claim. Why doesn't a cow own its body? He slides from my ownership of my laborious efforts to my ownership of what I have been working on. I can't acquire your car by servicing it. |
| 19884 | There is only a civil society if the members give up all of their natural executive rights [Locke] |
| Full Idea: Wherever any number of men so unite into one society as to quite every one his executive power of the law of Nature, and to resign it to the public, there and there only is a civil society. | |
| From: John Locke (Second Treatise of Government [1690], 089) | |
| A reaction: This seems to mean that you must give up your active ('executive') natural rights, but not your passive ones (which are inviolable). |
| 19879 | A man owns land if he cultivates it, to the limits of what he needs [Locke] |
| Full Idea: As much land as a man tills, plants, improves, cultivates, and can use the product of, so much is his property. | |
| From: John Locke (Second Treatise of Government [1690], 032) | |
| A reaction: Industrial farming rather changes this picture. Does the man himself decide how much he can use the product of, or do the neighbours tell him where his boundaries must be? 'Reason not the need', as King Lear said. What if he stops cultivating it? |
| 6580 | Locke (and Marx) held that ownership of objects is a natural relation, based on the labour put into it [Locke, by Fogelin] |
| Full Idea: Locke thought that property ownership reflected a natural relationship; for him the primordial notion of the ownership of an object is a function of the labour that one puts into it; Marx held a similar view. | |
| From: report of John Locke (Second Treatise of Government [1690]) by Robert Fogelin - Walking the Tightrope of Reason Ch.3 | |
| A reaction: Marx would have to think that, in order to believe that capitalist ownership of the means of production used by the workers was a fundamental injustice. A deeper Marxism might see the whole idea of 'ownership' as a capitalist (or feudal) conspiracy. |
| 20520 | Locke says 'mixing of labour' entitles you to land, as well as nuts and berries [Wolff,J on Locke] |
| Full Idea: The great advantage of Locke's 'labour-mixing' argument is that it seems it can justify the appropriation of land, as well as nuts and berries. | |
| From: comment on John Locke (Second Treatise of Government [1690]) by Jonathan Wolff - An Introduction to Political Philosophy (Rev) 5 'Locke' | |
| A reaction: The argument is dubious at best, and plausibly downright wicked. How much labour achieves ownership? What of previous people who worked the land but never thought to claim 'ownership'? Suppose I do more labour than you on 'your' land? |
| 19875 | A man's labour gives ownership rights - as long as there are fair shares for all [Locke] |
| Full Idea: The 'labour' being the unquestionable property of the labourer, no man but he can have a right to what that is once joined to, at least where there is enough, and as good left in common for others. | |
| From: John Locke (Second Treatise of Government [1690], 027) | |
| A reaction: The qualification at the end is a crucial (and problematic) addition to his theory. What is the situation when an area of wilderness is 98% owned? What of the single source of water? Who gets the best parts? Getting there first seems crucial. |
| 19874 | If a man mixes his labour with something in Nature, he thereby comes to own it [Locke] |
| Full Idea: Whatever a man removes out of the state that Nature hath provided and left it in, he hath mixed his labour with it, and joined something to it that is his own, and thereby makes it his property. ...This excludes the common right of other men. | |
| From: John Locke (Second Treatise of Government [1690], 027) | |
| A reaction: This is Locke's famous Labour Theory of Value. Does picking it up count as labour? Putting a fence round it? Paying someone else to do the labour? Do bees own their honey? Settlers in the wilderness own nothing on day one? |
| 19877 | Fountain water is everyone's, but a drawn pitcher of water has an owner [Locke] |
| Full Idea: Though the water running in the fountain be every one's, yet who can doubt but that in the pitcher is his only who drew it out? | |
| From: John Locke (Second Treatise of Government [1690], 029) | |
| A reaction: This would certainly be the normal consensus of a community, as long as there is plenty of water. The strong and fit gatherers get all the best firewood, so I suppose that is just tough on the others. |
| 19876 | Gathering natural fruits gives ownership; the consent of other people is irrelevant [Locke] |
| Full Idea: If the first gathering of acorns and apples made them not a man's, nothing else could. ...Will anyone say he had no right to them because he had not the consent of all mankind to make them his? | |
| From: John Locke (Second Treatise of Government [1690], 028) | |
| A reaction: The ideas of Nozick are all in this sentence. Does this idea justify the enclosure of common land? The first member of the community who thought of Locke's labour theory had a huge head's start. Liberal individualism rampant. |
| 19878 | Mixing labour with a thing bestows ownership - as long as the thing is not wasted [Locke] |
| Full Idea: How far has God given us all things 'to enjoy'? As much as any one can make use of to any advantage of his life before it spoils, so much he may by his labour fix a property in. | |
| From: John Locke (Second Treatise of Government [1690], 031) | |
| A reaction: This adds a very different value to Locke's theory, because the person seems to be answerable to fellow citizens if they harvest important resources and then waste them. Where do luxuries fit in? |
| 19898 | Soldiers can be commanded to die, but not to hand over their money [Locke] |
| Full Idea: The sergeant that can command a soldier to march up to the mouth of a cannon ...cannot command that soldier to give him one penny of his money. | |
| From: John Locke (Second Treatise of Government [1690], 139) | |
| A reaction: A very nice and accurate illustration of a principle which runs so deep that it does indeed look like a basis of society. |
| 19881 | The aim of law is not restraint, but to make freedom possible [Locke] |
| Full Idea: The end of law is not to abolish or restrain, but to preserve and enlarge freedom, for where there is no law there is no freedom. | |
| From: John Locke (Second Treatise of Government [1690], 057) | |
| A reaction: This fits both the liberal and the communitarian view of the matter. Talk of 'freedom' is commonplace in England by this date, where it is hardly mention 60 years earler. John Lilburne almost single-handedly brought this about. |
| 19868 | It is only by a law of Nature that we can justify punishing foreigners [Locke] |
| Full Idea: If by the law of Nature every man hath not a power to punish offences against [the state], as he soberly judges the case to require, I see not how the magistrates of any community can punish an alien of another country. | |
| From: John Locke (Second Treatise of Government [1690], 009) | |
| A reaction: This is a nice point. You can't expect to be above the law in a foreign country, but you have entered into no social contract, unless visiting a place is a sort of contract. Intrusions into air space are often accidental visits. |
| 19867 | Reparation and restraint are the only justifications for punishment [Locke] |
| Full Idea: Reparation and restraint are the only two reasons why one man may lawfully do harm to another, which is that we call punishment. | |
| From: John Locke (Second Treatise of Government [1690], 008) | |
| A reaction: But by 'reparation' does be mean retribution, or compensation? He doesn't rule out capital punishment, but that may qualify as maximum restraint. |
| 19912 | Self-defence is natural, but not the punishment of superiors by inferiors [Locke] |
| Full Idea: It is natural for us to defend life and limb, but that an inferior should punish a superior is against nature. | |
| From: John Locke (Second Treatise of Government [1690], 236) | |
| A reaction: He is obliquely referring to the execution of Charles I, even though he may have been legitimately overthrown. I wonder what exactly he means by 'superior' and 'inferior'. An idea from another age! |
| 19869 | Punishment should make crime a bad bargain, leading to repentance and deterrence [Locke] |
| Full Idea: Each transgression may be punished to that degree, and with so much severity, as will suffice to make it an ill bargain to the offender, give him cause to repent, and terrify others from doing the like. | |
| From: John Locke (Second Treatise of Government [1690], 012) | |
| A reaction: I gather that the consensus among experts is that the biggest deterrence is a high likelihood of being caught, rather than the severity of the punishment. |
| 19899 | The consent of the people is essential for any tax [Locke] |
| Full Idea: The legislative power must not raise taxes on the property of the people without the consent of the people given by themselves or their deputies. | |
| From: John Locke (Second Treatise of Government [1690], 142) | |
| A reaction: He will be thinking of the resistance to Ship Money in the 1630s, which was a step towards civil war. The people of Boston, Ma, may have read this sentence 80 years later! |
| 1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
| Full Idea: Archelaus was the first person to say that the universe is boundless. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3 |
| 5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |
| Full Idea: Archelaus wrote that life on Earth began in a primeval slime. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus | |
| A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea. |