14 ideas
14970 | Normal system K has five axioms and rules [Cresswell] |
14971 | D is valid on every serial frame, but not where there are dead ends [Cresswell] |
14972 | S4 has 14 modalities, and always reduces to a maximum of three modal operators [Cresswell] |
14973 | In S5 all the long complex modalities reduce to just three, and their negations [Cresswell] |
14976 | Reject the Barcan if quantifiers are confined to worlds, and different things exist in other worlds [Cresswell] |
14974 | A relation is 'Euclidean' if aRb and aRc imply bRc [Cresswell] |
12312 | The real essence of a thing is its powers, or 'dispositional properties' [Copi] |
12887 | A whole must have one characteristic, an internal relation, and a structure [Rescher/Oppenheim] |
10937 | Essential properties are the 'deepest' ones which explain the others [Copi, by Rami] |
12308 | In modern science, nominal essence is intended to be real essence [Copi] |
12303 | Within the four types of change, essential attributes are those whose loss means destruction [Copi] |
14975 | A de dicto necessity is true in all worlds, but not necessarily of the same thing in each world [Cresswell] |
12307 | Modern science seeks essences, and is getting closer to them [Copi] |
12310 | Real essences are scientifically knowable, but so are non-essential properties [Copi] |