18 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. |
| 20991 | People prepare our dinner from their own self-interest, not from humanity [Smith,A] |
| Full Idea: It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own interest. We address ourselves, not to their humanity but to their self-love. | |
| From: Adam Smith (The Wealth of Nations [1776], p.26-7), quoted by Amartya Sen - The Idea of Justice 08 'Narrowing' | |
| A reaction: Sen passionately pleads that this not be taken out of context. It is about the motivation for the relationship of exchange, and not about morality in general, which also includes trust etc. The subsequent lines in Smith show this. |
| 7127 | If men are good you should keep promises, but they aren't, so you needn't [Machiavelli] |
| Full Idea: If all men were good, promising-breaking would not be good, but because they are bad and do not keep their promises to you, you likewise do not have to keep yours to them. | |
| From: Niccolo Machiavelli (The Prince [1513], Ch.18) | |
| A reaction: A rather depressing proposal to get your promise-breaking in first, based on the pessimistic view that people cannot be improved. The subsequent history of ethics in Europe showed Machiavelli to be wrong. Gentlemen began to keep their word. |
| 6309 | The principle foundations of all states are good laws and good armies [Machiavelli] |
| Full Idea: The principle foundations of all states are good laws and good armies. | |
| From: Niccolo Machiavelli (The Prince [1513], Ch.11) | |
| A reaction: We may be wondering, since 1945, whether a good army is any longer essential, but it would be a foolish modern state which didn't at least form a strong alliance with a state which had a strong army. Fertile land is a huge benefit to a state. |
| 6306 | People are vengeful, so be generous to them, or destroy them [Machiavelli] |
| Full Idea: Men should be either treated generously or destroyed, because they take revenge for slight injuries. | |
| From: Niccolo Machiavelli (The Prince [1513], Ch.3) | |
| A reaction: This sounds like good advice, and works quite well in school teaching too. It seems like advice drawn from the growth of the Roman Empire, rather than from dealing with sophisticated and educated people. |
| 6305 | To retain a conquered state, wipe out the ruling family, and preserve everything else [Machiavelli] |
| Full Idea: If a ruler acquires a state and is determined to keep it, he observes two cautions: he wipes out the family of their long-established princes; and he does not change either their laws or their taxes; in a short time they will unite with his old princedom. | |
| From: Niccolo Machiavelli (The Prince [1513], Ch.3) | |
| A reaction: This nicely illustrates the firmness of purpose for which Machiavelli has become a byword. The question is whether Machiavelli had enough empirical evidence to support this induction. The British in India seem to have been successful without it. |
| 6308 | A sensible conqueror does all his harmful deeds immediately, because people soon forget [Machiavelli] |
| Full Idea: A prudent conqueror makes a list of all the harmful deeds he must do, and does them all at once, so that he need not repeat them every day, which then makes men feel secure, and gains their support by treating them well. | |
| From: Niccolo Machiavelli (The Prince [1513], Ch.8) | |
| A reaction: This might work for a new government in a democracy, or a new boss in a business. It sounds horribly true; dreadful deeds done a long time ago can be completely forgotten, as when reformed criminals become celebrities. |
| 20680 | Selfish profit-seeking increases collective wealth, so greed is good, and egoism is altruism [Smith,A, by Harari] |
| Full Idea: Smith's claim that the selfish human urge to increase private profits is the basis for collective wealth is one of the most revolutionary ideas in human history. …Greed is good …and egoism is altruism. | |
| From: report of Adam Smith (The Wealth of Nations [1776]) by Yuval Noah Harari - Sapiens: brief history of humankind 16 'Growing' | |
| A reaction: The central confrontation of political philosophy still seems to be Adam Smith v Karl Marx. Why can't there be altruistic non-greedy profit-seeking? Not 'I want profits' but 'we want profits'. Altruistic capitalists aim to create jobs. |
| 6307 | A desire to conquer, and men who do it, are always praised, or not blamed [Machiavelli] |
| Full Idea: It is very natural and normal to wish to conquer, and when men do it who can, they always will be praised, or not blamed. | |
| From: Niccolo Machiavelli (The Prince [1513], Ch.3) | |
| A reaction: This view seems shocking to us, but it seems to me that this was a widely held view up until the time of Nietzsche, but came to a swift end with the invention of the machine gun in about 1885, followed by the heavy bomber and atomic bomb. |
| 7486 | Machiavelli emancipated politics from religion [Machiavelli, by Watson] |
| Full Idea: Machiavelli emancipated politics from religion. | |
| From: report of Niccolo Machiavelli (The Prince [1513]) by Peter Watson - Ideas Ch.24 | |
| A reaction: Interestingly, he seems to have done it by saying that ideals are irrelevant to politics, but gradually secular ideals crept back in (sometimes disastrously). A balance needs to be struck on idealism. |