15 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. |
| 23857 | People in power always try to increase their power [Weil] |
| Full Idea: Every human group that exercises power does so …in such a way as to increase that power. | |
| From: Simone Weil (Prospects: Proletarian Revolution? [1933], p.15) | |
| A reaction: Not so true in smaller institutions, but at the centre of power you can control how power is distributed, so the temptation is too much. |
| 23856 | Spontaneous movements are powerless against organised repression [Weil] |
| Full Idea: A spontaneous movement is fundamentally impotent when it comes to fighting against organised forces of repression. | |
| From: Simone Weil (Prospects: Proletarian Revolution? [1933], p.2) | |
| A reaction: Her example is the Paris Commune of 1870. Hence revolution requires prior penetration of the corridors of power. Hence the phenomenon of 'entryism' of more radical people into reformist parties. |
| 23859 | True democracy is the subordination of society to the individual [Weil] |
| Full Idea: In the subordination of society to the individual lies the definition of true democracy, and that of socialism as well. | |
| From: Simone Weil (Prospects: Proletarian Revolution? [1933], p.19) | |
| A reaction: This is the simplest definition of the liberal view. The big difference is whether this subordination is the starting point of political thinking, or the end result at which it aims. |
| 1658 | In early Greece the word for punishment was also the word for vengeance [Vlastos] |
| Full Idea: Down to the last third of the fifth century, 'timoria', whose original and always primary sense is "vengeance", is THE word for "punishment". | |
| From: Gregory Vlastos (Socrates: Ironist and Moral Philosopher [1991], p.186) |
| 23858 | War is perpetuated by its continual preparations [Weil] |
| Full Idea: War perpetuates itself under the form of preparation for war. | |
| From: Simone Weil (Prospects: Proletarian Revolution? [1933], p.16) | |
| A reaction: There are periods when military preparations are scaled down, but a reason is always found to scale them back up again. |
| 23860 | Even if a drowning man is doomed, he should keep swimming to the last [Weil] |
| Full Idea: A man who is thrown overboard in the middle of the ocean ought not to let himself drown, even though there is very litte chance of his reaching safety, but to go on swimming till exhausted. | |
| From: Simone Weil (Prospects: Proletarian Revolution? [1933], p.21) | |
| A reaction: You might survive a little longer if you don't exhaust yourself! Not clear where her authority for 'ought' comes from, but it expresses an interesting attitude. |