11 ideas
15585 | Later Heidegger sees philosophy as more like poetry than like science [Heidegger, by Polt] |
Full Idea: In his later work Heidegger came to view philosophy as closer to poetry than to science. | |
From: report of Martin Heidegger (The Origin of the Work of Art [1935], p.178) by Richard Polt - Heidegger: an introduction 5 'Signs' |
13445 | Descartes showed a one-one order-preserving match between points on a line and the real numbers [Descartes, by Hart,WD] |
Full Idea: Descartes founded analytic geometry on the assumption that there is a one-one order-preserving correspondence between the points on a line and the real numbers. | |
From: report of René Descartes (works [1643]) by William D. Hart - The Evolution of Logic 1 |
18253 | I wish to go straight from cardinals to reals (as ratios), leaving out the rationals [Frege] |
Full Idea: You need a double transition, from cardinal numbes (Anzahlen) to the rational numbers, and from the latter to the real numbers generally. I wish to go straight from the cardinal numbers to the real numbers as ratios of quantities. | |
From: Gottlob Frege (Letters to Russell [1902], 1903.05.21), quoted by Michael Dummett - Frege philosophy of mathematics 21 'Frege's' | |
A reaction: Note that Frege's real numbers are not quantities, but ratios of quantities. In this way the same real number can refer to lengths, masses, intensities etc. |
18166 | The loss of my Rule V seems to make foundations for arithmetic impossible [Frege] |
Full Idea: With the loss of my Rule V, not only the foundations of arithmetic, but also the sole possible foundations of arithmetic, seem to vanish. | |
From: Gottlob Frege (Letters to Russell [1902], 1902.06.22) | |
A reaction: Obviously he was stressed, but did he really mean that there could be no foundation for arithmetic, suggesting that the subject might vanish into thin air? |
18269 | Logical objects are extensions of concepts, or ranges of values of functions [Frege] |
Full Idea: How are we to conceive of logical objects? My only answer is, we conceive of them as extensions of concepts or, more generally, as ranges of values of functions ...what other way is there? | |
From: Gottlob Frege (Letters to Russell [1902], 1902.07.28), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 7 epigr | |
A reaction: This is the clearest statement I have found of what Frege means by an 'object'. But an extension is a collection of things, so an object is a group treated as a unity, which is generally how we understand a 'set'. Hence Quine's ontology. |
16774 | Descartes thinks distinguishing substances from aggregates is pointless [Descartes, by Pasnau] |
Full Idea: Descartes thinks it is a pointless relic of scholastic metaphysics to dispute over the boundaries between substances and mere aggregates. | |
From: report of René Descartes (works [1643]) by Robert Pasnau - Metaphysical Themes 1274-1671 25.6 | |
A reaction: This is Pasnau's carefully considered conclusion, with which others may not agree. It presumably captures the attitude of modern science generally to such issues. |
7400 | Descartes said images can refer to objects without resembling them (as words do) [Descartes, by Tuck] |
Full Idea: Descartes argued (in 'The World') that just as words refer to objects, but they do not resemble them, in the same way, visual images or other sensory inputs relate to objects without depicting them. | |
From: report of René Descartes (works [1643]) by Richard Tuck - Hobbes | |
A reaction: This strikes me as a rather significant and plausible claim, which might contain the germ of the idea of a language of thought. It is also the basis for the recent view that language is the best route to understanding the mind. |
4310 | We have inner awareness of our freedom [Descartes] |
Full Idea: We have inner awareness of our freedom. | |
From: René Descartes (works [1643]) | |
A reaction: This begs a few questions. I may be directly aware that I have not been hypnotised, but no one would accept it as proof. |
6553 | Descartes discussed the interaction problem, and compared it with gravity [Descartes, by Lycan] |
Full Idea: Descartes himself was well aware of the interaction problem, and corresponded uncomfortably with Princess Elizabeth on the matter; …he pointed out that gravity is causal despite not being a physical object. | |
From: report of René Descartes (works [1643]) by William Lycan - Consciousness n1.3 | |
A reaction: Lycan observes that at least gravity is in space-time, unlike the Cartesian mind. Pierre Gassendi had pointed out the problem to Descartes in the Fifth Objection to the 'Meditations' (see Idea 3400). |
19676 | Nature is devoid of thought [Descartes, by Meillassoux] |
Full Idea: It is Descartes who ratifies the idea that nature is devoid of thought. | |
From: report of René Descartes (works [1643]) by Quentin Meillassoux - After Finitude; the necessity of contingency 5 | |
A reaction: His dualism is crucial, along with his ontological argument, because they make all mentality supernatural. Remember, for Descartes animals are mindless machines. |
6518 | Matter can't just be Descartes's geometry, because a filler of the spaces is needed [Robinson,H on Descartes] |
Full Idea: Notoriously, the Cartesian idea that matter is purely geometrical will not do, for it leaves no distinction between matter and empty volumes: a filler for these volumes is required. | |
From: comment on René Descartes (works [1643]) by Howard Robinson - Perception IX.3 | |
A reaction: Descartes thinks of matter as 'extension'. Descartes's error seems so obvious that it is a puzzle why he made it. He may have confused epistemology and ontology - all we can know of matter is its extension in space. |