6 ideas
9184 | We can't presume that all interesting concepts can be analysed [Williamson] |
Full Idea: We have no prior reason to suppose that philosophically significant concepts have interesting analyses into necessary and sufficient conditions. | |
From: Timothy Williamson (Review of Bob Hale's 'Abstract Objects' [1988]) | |
A reaction: We might think that they are either analysable or primitive, and that failure of analysis invites us to take a concept as primitive. But maybe God can analyse it and we can't. |
16974 | The nature of each logical concept is given by a collection of inference rules [Correia] |
Full Idea: The view presented here presupposes that each logical concept is associated with some fixed and well defined collection of rules of inference which characterize its basic logical nature. | |
From: Fabrice Correia (On the Reduction of Necessity to Essence [2012], 4) | |
A reaction: [He gives Fine's 'Senses of Essences' 57-8 as a source] He seems to have in mind natural deduction, where the rules are for the introduction and elimination of the concepts. |
9183 | Platonism claims that some true assertions have singular terms denoting abstractions, so abstractions exist [Williamson] |
Full Idea: The Fregean argument for platonism is that some true assertions contain singular terms which denote abstract objects if they denote anything; since the assertions are true, the singular terms denote. | |
From: Timothy Williamson (Review of Bob Hale's 'Abstract Objects' [1988]) | |
A reaction: I am perplexed that anyone would rest their view of reality on such an argument. The obvious comparison would be with true remarks about blatantly fictional characters, or blatantly invented concepts such as 'checkmate'. |
16973 | Explain logical necessity by logical consequence, or the other way around? [Correia] |
Full Idea: One view is that logical consequence is to be understood in terms of logical necessity (some proposition holds necessarily, if some group of other propositions holds). Alternatively, logical necessity is a logical consequence of the empty set. | |
From: Fabrice Correia (On the Reduction of Necessity to Essence [2012], 3) | |
A reaction: I think my Finean preference is for all necessities to have a 'necessitator', so logical necessity results from logic in some way, perhaps from logical consequence, or from the essences of the connectives and operators. |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |