26 ideas
| 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. |
| 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. |
| 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. |
| 17064 | 1: Coherence is a symmetrical relation between two propositions [Thagard, by Smart] |
| Full Idea: 1: Coherence and incoherence are symmetrical between pairs of propositions. | |
| From: report of Paul Thagard (Explanatory Coherence [1989], 1) by J.J.C. Smart - Explanation - Opening Address p.04 |
| 17065 | 2: An explanation must wholly cohere internally, and with the new fact [Thagard, by Smart] |
| Full Idea: 2: If a set of propositions explains a further proposition, then each proposition in the set coheres with that proposition, and propositions in the set cohere pairwise with one another. | |
| From: report of Paul Thagard (Explanatory Coherence [1989], 2) by J.J.C. Smart - Explanation - Opening Address p.04 |
| 17066 | 3: If an analogous pair explain another analogous pair, then they all cohere [Thagard, by Smart] |
| Full Idea: 3: If two analogous propositions separately explain different ones of a further pair of analogous propositions, then the first pair cohere with one another, and so do the second (explananda) pair. | |
| From: report of Paul Thagard (Explanatory Coherence [1989], 3) by J.J.C. Smart - Explanation - Opening Address p.04 |
| 17067 | 4: For coherence, observation reports have a degree of intrinsic acceptability [Thagard, by Smart] |
| Full Idea: 4: Observation reports (for coherence) have a degree of acceptability on their own. | |
| From: report of Paul Thagard (Explanatory Coherence [1989], 4) by J.J.C. Smart - Explanation - Opening Address p.04 | |
| A reaction: Thagard makes this an axiom, but Smart rejects that and says there is no reason why observation reports should not also be accepted because of their coherence (with our views about our senses etc.). I agree with Smart. |
| 17068 | 5: Contradictory propositions incohere [Thagard, by Smart] |
| Full Idea: 5: Contradictory propositions incohere. | |
| From: report of Paul Thagard (Explanatory Coherence [1989], 5) by J.J.C. Smart - Explanation - Opening Address p.04 | |
| A reaction: This has to be a minimal axiom for coherence, but coherence is always taken to be more than mere logical consistency. Mutual relevance is the first step. At least there must be no category mistakes. |
| 17069 | 6: A proposition's acceptability depends on its coherence with a system [Thagard, by Smart] |
| Full Idea: 6: Acceptability of a proposition in a system depends on its coherence with the propositions in that system. | |
| From: report of Paul Thagard (Explanatory Coherence [1989], 6) by J.J.C. Smart - Explanation - Opening Address p.04 | |
| A reaction: Thagard tried to build an AI system for coherent explanations, but I would say he has no chance with these six axioms, because they never grasp the nettle of what 'coherence' means. You first need rules for how things relate. What things are comparable? |
| 23874 | Armies and businesses create moralities in which their activity can do no wrong [Marx, by Weil] |
| Full Idea: Marx saw that social groups manufacture moralities for their own use, so their activity is placed outside the reach of evil. Thus the first articles of soldiers and businessmen is to deny that it is possible to do evil while waging war or doing business. | |
| From: report of Karl Marx (works [1860]) by Simone Weil - Fragments: London 1943 p.146 | |
| A reaction: This is especially true of the modern reverence for 'market forces'. It is a key debate in the ethics of warfare - compare Walzer and McMahon. A striking thought, obviously containing a lot of truth. |
| 18662 | Liberal freedom is the right to be separate, and ignores the union of man with man [Marx] |
| Full Idea: The liberal right of man to freedom is not based on the union of man with man, but on the separation of man from man; it is the right to this separation. | |
| From: Karl Marx (works [1860]), quoted by Will Kymlicka - Contemporary Political Philosophy (1st edn) 7.2.a | |
| A reaction: [quoted from an anthology] It is interesting that liberal freedom is the right NOT to be involved in politics, and even not to vote in elections. Home counties England (high hedges etc) is the embodiment of the freedom not to be involved in society. |
| 23372 | Liberals want the right to be separate, rather than for people to be united [Marx] |
| Full Idea: The [liberal] right of man to freedom is not based on the union of man with man, but on the separation of man from man. It is the right to this separation. | |
| From: Karl Marx (works [1860], p.53), quoted by Will Kymlicka - Contemporary Political Philosophy (2nd edn) 7 | |
| A reaction: [in collection ed.McLelland p.53] That nicely encapsulates the debate. Modern liberal thinkers regret the loss of community, but people in authoritarian communities yearn for separation. You can have too much 'union'! |
| 20576 | Early Marx anticipates communitarian objections to liberalism [Marx, by Oksala] |
| Full Idea: The early writings of Marx anticipate the communitarian critique of liberalism. | |
| From: report of Karl Marx (works [1860]) by Johanna Oksala - Political Philosophy: all that matters Ch.8 | |
| A reaction: [Oksala says modern writers seem to prefer this to the hardcore later Marx, which is presumably too 'scientific'. He says 'Capital Vol 1' is Marx's most important work] |
| 23862 | By saying the material dialectic of history aspires to the best, Marx agreed with capitalism [Weil on Marx] |
| Full Idea: When Marx inverted Hegel's dialectic of history, by substituting matter for mind as the motive, he attributed to matter the essence of mind, an unceasing aspiration towards the best - which was in keeping with the general current of capitalist thought. | |
| From: comment on Karl Marx (works [1860]) by Simone Weil - Reflections on Liberty and Social Oppression p.43 | |
| A reaction: [compressed] A rather nice debating point! Marx seems to share the universal nineteenth century belief in unremitting progress. Without that, it is impossible to believe that a revolution will necessarily improve anything. |
| 21999 | False consciousness results from concealment by the superstructure [Marx, by Singer] |
| Full Idea: False consciousness involves failing to see things as they really are. It comes about because a society's superstructure can conceal the real basis of the society. | |
| From: report of Karl Marx (works [1860]) by Peter Singer - Marx 9 | |
| A reaction: That seems a poor label, probably revealing a Hegelian background. It seems a matter of knowledge rather than consciousness. Can a whole mind be in a state of error? |
| 23875 | Marx says force is everything, and that the weak will become strong, while remaining the weak [Weil on Marx] |
| Full Idea: Marx posits on the one hand that force alone governs social relations to the exclusion of anything else, and on the other hand that one day the weak, while remaining weak, will nevertheless be stronger. He believed in miracles. | |
| From: comment on Karl Marx (works [1860]) by Simone Weil - Fragments: London 1943 p.149 | |
| A reaction: This is close to the obvious contradiction if the working classes despise the middle classes (the dreaded 'bourgeoisie') while their only aspiration is to be like them. It is hard to custom design a new class to which they could both aspire. |
| 18653 | Marx rejected equal rights because they never actually treat people as equals [Marx, by Kymlicka] |
| Full Idea: Marx rejected the idea of equal rights, not because he was not a friend to the idea of treating people as equals, but precisely because he thought rights failed to live up to that ideal. | |
| From: report of Karl Marx (works [1860]) by Will Kymlicka - Contemporary Political Philosophy (1st edn) 5.1 | |
| A reaction: Presumably because the power to award 'rights' goes to the highest bidder. If equality is to be enshrined in law, it is a bit difficult to see how else to manage it. |
| 20958 | Capitalism changes the world, by socialising the idea of a commodity [Marx, by Bowie] |
| Full Idea: In Marx's view the essential factor in capitalism is that the encroachment of the commodity form into society fundamentally changes the world. | |
| From: report of Karl Marx (works [1860]) by Andrew Bowie - Introduction to German Philosophy 6 'Historical' | |
| A reaction: The main point is that people and their labour become commodities. Haven't animals always been treated as commodities? Clearly slave were commodities, long before capitalism. Capitalism universalises it? |
| 23876 | The essence of capitalism is the subordination of people to things [Marx, by Weil] |
| Full Idea: Marx discovered a formula impossible to surpass when he said that the essence of capitalism lies in the subordination of subject to object, of man to thing. | |
| From: report of Karl Marx (works [1860]) by Simone Weil - Fragments: London 1943 p,155 | |
| A reaction: I find this rather too vague to be a penetrating observation. I would suggest the obliteration of cooperation and community, in favour of competition. Winners and losers. |
| 20960 | Marx thought capitalism was partly liberating, and could make labour and ownership more humane [Marx, by Bowie] |
| Full Idea: Marx did not disapprove per se of capitalism. New divisions of labour and forms of ownership could transform individuals in modern societies, creating a more humane world with the means capitalism had liberated from feudalism. | |
| From: report of Karl Marx (works [1860]) by Andrew Bowie - Introduction to German Philosophy 11 'Metaphysics' | |
| A reaction: I'm guessing this might be early Marx, which has less to say about the 'scientific' inevitably of deep change, and the necessity for revolution. Nowadays we tinker with humane changes at the poorer end, while the rich run rampant. |