11 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. |
22014 | Consciousness is not entirely representational, because there are pains, and the self [Schulze, by Pinkard] |
Full Idea: Schulze said Reinhold and Kant violated their own theory with the thing-in-itself, and that Reinhold was wrong that all consciousnes is representational (since pain isn't), and the self can't represent itself without a regress. | |
From: report of Gottlob Schulze (Aenesidemus [1792]) by Terry Pinkard - German Philosophy 1760-1860 05 | |
A reaction: [my compressed version] This article demolished Reinhold, which is a shame, because if he had responded constructively to these criticisms he might have reached be best theory of his age. These are analytic style objections, by counterexample. |
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. |
7844 | The Golden Rule is accepted everywhere, and gives a fixed target for morality [Voltaire] |
Full Idea: Pascal asks where we can find a fixed point in morality. The answer is in that single maxim accepted by all nations: "Do not do to others what you would not like to have done to you". | |
From: Francois-Marie Voltaire (Philosophical Letters from England [1733], 25) | |
A reaction: Should I only offer to my guests foods which I myself like? If I don't mind a bit of pain, is it all right to inflict it? It is a sensible rule, but not precise enough for philosophy. |