5 ideas
| 7791 | The simplest of the logics based on possible worlds is Lewis's S5 [Lewis,CI, by Girle] |
| Full Idea: C.I.Lewis constructed five axiomatic systems of modal logic, and named them S1 to S5. It turns out that the simplest of the logics based on possible worlds is the same as Lewis's S5. | |
| From: report of C.I. Lewis (works [1935]) by Rod Girle - Modal Logics and Philosophy 2.1 | |
| A reaction: Nathan Salmon ('Reference and Essence' 2nd ed) claims (on p.xvii) that "the correct modal logic is weaker than S5 and weaker even than S4". Which is the greater virtue, simplicity or weakness? |
| 5060 | All substances analyse down to simple substances, which are souls, or 'monads' [Leibniz] |
| Full Idea: What (in the analysis of substances) exist ultimately are simple substances - namely, souls, or, if you prefer a more general terms, 'monads', which are without parts. | |
| From: Gottfried Leibniz (Metaphysical conseqs of principle of reason [1712], §7) | |
| A reaction: This seems to me to be atomistic panpsychism. He is opposed to physical atomism, because infinite divisibility seems obvious, but unity is claimed to be equally obvious in the world of the mental. Does this mean bricks are made of souls? Odd. |
| 11002 | Equating necessity with informal provability is the S4 conception of necessity [Lewis,CI, by Read] |
| Full Idea: C.I.Lewis's S4 system develops a sense of necessity as 'provability' in some fairly informal sense. | |
| From: report of C.I. Lewis (works [1935]) by Stephen Read - Thinking About Logic Ch. 4 |
| 8130 | Qualities of experience are just representational aspects of experience ('Representationalism') [Harman, by Burge] |
| Full Idea: Harman defended what came to be known as 'representationalism' - the view that qualitative aspects of experience are nothing other than representational aspects. | |
| From: report of Gilbert Harman (The Intrinsic Quality of Experience [1990]) by Tyler Burge - Philosophy of Mind: 1950-2000 p.459 | |
| A reaction: Functionalists like Harman have a fairly intractable problem with the qualities of experience, and this may be clutching at straws. What does 'represent' mean? How is the representation achieved? Why that particular quale? |
| 5059 | Power rules in efficient causes, but wisdom rules in connecting them to final causes [Leibniz] |
| Full Idea: In all of nature efficient causes correspond to final causes, because everything proceeds from a cause which is not only powerful, but wise; and with the rule of power through efficient causes, there is involved the rule of wisdom through final causes. | |
| From: Gottfried Leibniz (Metaphysical conseqs of principle of reason [1712], §5) | |
| A reaction: Nowadays this carrot-and-stick view of causation is unfashionable, but I won't rule it out. The deepest 'why?' we can ask won't just go away. This unity by a divine mind strikes me as too simple, but Leibniz is right to try to unify Aristotelian causes. |