18739 | Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) |
18741 | Logical formalization makes concepts precise, and also shows their interrelation |
18744 | Models are sets with functions and relations, and truth built up from the components |
18740 | If 'exist' doesn't express a property, we can hardly ask for its essence |
18745 | A Tarskian model can be seen as a possible state of affairs |
18747 | The 'spheres model' was added to possible worlds, to cope with counterfactuals |
18748 | Epistemic logic introduced impossible worlds |
18746 | Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment |
18750 | Using possible worlds for knowledge and morality may be a step too far |
18749 | Goodman argued that the confirmation relation can never be formalised |