9 ideas
| 8859 | The main modal logics disagree over three key formulae [Yablo] |
| Full Idea: Lewis's different systems of modal logic differed about such formulae as □P implies □□P; ◊□P implies □P; and ◊S implies □◊S | |
| From: Stephen Yablo (Apriority and Existence [2000], §06) | |
| A reaction: Yablo's point is that the various version don't seem to make much difference to our practices in logic, mathematics and science. The problem, says Yablo, is deciding exactly what you mean by 'necessarily' and 'possibly'. |
| 8865 | If 'the number of Democrats is on the rise', does that mean that 50 million is on the rise? [Yablo] |
| Full Idea: If someone says 'the number of Democrats is on the rise', he or she wants to focus on Democrats, not numbers. If the number is 50 million, is 50 million really on the rise? | |
| From: Stephen Yablo (Apriority and Existence [2000], §14) | |
| A reaction: This is a very nice warning from Yablo, against easy platonism, or any sort of platonism at all. We routinely say that numbers are 'increasing', but the real meaning needs entangling. Here it refers to people joining a party. |
| 19406 | I strongly believe in the actual infinite, which indicates the perfections of its author [Leibniz] |
| Full Idea: I am so much for the actual infinite that instead of admitting that nature abhors it, as is commonly said, I hold that it affects nature everywhere in order to indicate the perfections of its author. | |
| From: Gottfried Leibniz (Reply to Foucher [1693], p.99) | |
| A reaction: I would have thought that, for Leibniz, while infinities indicate the perfections of their author, that is not the reason why they exist. God wasn't, presumably, showing off. Leibniz does not think we can actually know these infinities. |
| 8863 | We must treat numbers as existing in order to express ourselves about the arrangement of planets [Yablo] |
| Full Idea: It is only by making as if to countenance numbers that one can give expression in English to a fact having nothing to do with numbers, a fact about stars and planets and how they are numerically proportioned. | |
| From: Stephen Yablo (Apriority and Existence [2000], §13) | |
| A reaction: To avoid the phrase 'numerically proportioned', he might have alluded to the 'pattern' of the stars and planets. I'm not sure which -ism this is, but it seems to me a good approach. The application is likely to precede the theory. |
| 8862 | Platonic objects are really created as existential metaphors [Yablo] |
| Full Idea: The means by which platonic objects are simulated is existential metaphor. Numbers are conjured up as metaphorical measures of cardinality. | |
| From: Stephen Yablo (Apriority and Existence [2000], §12) | |
| A reaction: 'Fictional' might be a better word than 'metaphorical', since the latter usually implies some sort of comparison. |
| 8864 | We quantify over events, worlds, etc. in order to make logical possibilities clearer [Yablo] |
| Full Idea: It is not that the contents of sentences are inexpressible without quantifying over events, worlds, etc. (they aren't). But the logical relations become much more tractable if we represent them quantificationally. | |
| From: Stephen Yablo (Apriority and Existence [2000], §13) | |
| A reaction: Yablo is explaining why we find ourselves committed to abstract objects. It is essentially, as I am beginning to suspect, a conspiracy of logicians. What on earth is 'the empty set' when it is at home? What's it made of? |
| 8858 | Philosophers keep finding unexpected objects, like models, worlds, functions, numbers, events, sets, properties [Yablo] |
| Full Idea: There's a tradition in philosophy of finding 'unexpected objects' in truth-conditions, such as countermodels, possible worlds, functions, numbers, events, sets and properties. | |
| From: Stephen Yablo (Apriority and Existence [2000], §02) | |
| A reaction: This is a very nice perspective on the whole matter of abstract objects. If we find ourselves reluctantly committed to the existence of something which is ontologically peculiar, we should go back to the philosophical drawing-board. |
| 19392 | I don't recommend universal doubt; we constantly seek reasons for things which are indubitable [Leibniz] |
| Full Idea: I do not think it necessary to recommend to people universal doubt ...in fact, we are constantly seeking reasons for thoughts about which there is no doubt at all. | |
| From: Gottfried Leibniz (Precepts for Advancing Science and Arts [1680], p.34) | |
| A reaction: Such confidence is, of course, asking for trouble. I prefer Peirce's fallibilism - that robust realism is the most coherent view, and the only one worth pursuing and relying on, but you never know.... |
| 8861 | Hardly a word in the language is devoid of metaphorical potential [Yablo] |
| Full Idea: There is hardly a word in the language - be it an adverb, preposition, conjunction, or what have you - that is devoid of metaphorical potential. | |
| From: Stephen Yablo (Apriority and Existence [2000], §12) | |
| A reaction: Yablo goes on to claim that metaphor is at the heart of all of our abstract thinking. 'Dead metaphors' (like the "mouth" of a river) sink totally into literal language. I think Yablo is on the right lines. |