30 ideas
12463 | Unlike correspondence, truthmaking can be one truth to many truthmakers, or vice versa [Jacobs] |
13913 | The four 'perfect syllogisms' are called Barbara, Celarent, Darii and Ferio [Engelbretsen/Sayward] |
13914 | Syllogistic logic has one rule: what is affirmed/denied of wholes is affirmed/denied of their parts [Engelbretsen/Sayward] |
13915 | Syllogistic can't handle sentences with singular terms, or relational terms, or compound sentences [Engelbretsen/Sayward] |
13916 | Term logic uses expression letters and brackets, and '-' for negative terms, and '+' for compound terms [Engelbretsen/Sayward] |
13850 | In modern logic all formal validity can be characterised syntactically [Engelbretsen/Sayward] |
13849 | Classical logic rests on truth and models, where constructivist logic rests on defence and refutation [Engelbretsen/Sayward] |
18739 | Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) [Horsten/Pettigrew] |
13851 | Unlike most other signs, = cannot be eliminated [Engelbretsen/Sayward] |
18741 | Logical formalization makes concepts precise, and also shows their interrelation [Horsten/Pettigrew] |
18744 | Models are sets with functions and relations, and truth built up from the components [Horsten/Pettigrew] |
13852 | Axioms are ω-incomplete if the instances are all derivable, but the universal quantification isn't [Engelbretsen/Sayward] |
18740 | If 'exist' doesn't express a property, we can hardly ask for its essence [Horsten/Pettigrew] |
14375 | If structures result from intrinsic natures of properties, the 'relations' between them can drop out [Jacobs] |
14378 | Science aims at identifying the structure and nature of the powers that exist [Jacobs] |
12467 | Powers come from concrete particulars, not from the laws of nature [Jacobs] |
14377 | Possibilities are manifestations of some power, and impossibilies rest on no powers [Jacobs] |
14376 | States of affairs are only possible if some substance could initiate a causal chain to get there [Jacobs] |
14379 | Counterfactuals invite us to consider the powers picked out by the antecedent [Jacobs] |
14372 | Possible worlds are just not suitable truthmakers for modality [Jacobs] |
12466 | All modality is in the properties and relations of the actual world [Jacobs] |
14371 | We can base counterfactuals on powers, not possible worlds, and hence define necessity [Jacobs] |
18745 | A Tarskian model can be seen as a possible state of affairs [Horsten/Pettigrew] |
18747 | The 'spheres model' was added to possible worlds, to cope with counterfactuals [Horsten/Pettigrew] |
18748 | Epistemic logic introduced impossible worlds [Horsten/Pettigrew] |
12465 | Concrete worlds, unlike fictions, at least offer evidence of how the actual world could be [Jacobs] |
12464 | If some book described a possibe life for you, that isn't what makes such a life possible [Jacobs] |
12469 | Possible worlds semantics gives little insight into modality [Jacobs] |
18746 | Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment [Horsten/Pettigrew] |
18750 | Using possible worlds for knowledge and morality may be a step too far [Horsten/Pettigrew] |