12 ideas
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 |
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. |
16978 | If conceivability is a priori coherence, that implies possibility [Tahko] |
Full Idea: Maybe conceivability could be understood as a priori coherence, which implies possibility. | |
From: Tuomas E. Tahko (The Epistemology of Essence (draft) [2013], 3.2) | |
A reaction: I'm not quite sure why 'a priori' has to be there. Assessing conceivability just is assessing coherence. That couches it as a rational activity, rather than as a purely imaginary one. Trying to conceive a square circle isn't just daydreaming. |
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. |
16975 | Essences are used to explain natural kinds, modality, and causal powers [Tahko] |
Full Idea: Essences are supposed to do a lot of explanatory work: natural kinds can be identified in terms of their essences, metaphysical modality can be reduced to essence, the causal power of objects can be explained with the help of essence. | |
From: Tuomas E. Tahko (The Epistemology of Essence (draft) [2013], 1) | |
A reaction: Natural kinds and modality are OK with me, but I'm dubious about the third one. If an essence explains something's causal powers, I have no idea what an essence might be. Essence are largely characterised in terms of causal powers. |
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? |
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. |
16976 | Scientific essentialists tend to characterise essence in terms of modality (not vice versa) [Tahko] |
Full Idea: The conception of essence taken for granted in much of the 'scientific essentialist' literature is that essence can be explained in terms of modality (rather than the other way round). | |
From: Tuomas E. Tahko (The Epistemology of Essence (draft) [2013], 2.1) | |
A reaction: [He cites Ellis and Bird] That is, presumably, that they are inclined to say that the essence of gold is a set of necessary properties. Maybe conceptual necessities dictate the properties of gold, and they in turn dictate metaphysical necessities? |
16977 | If essence is modal and laws are necessary, essentialist knowledge is found by scientists [Tahko] |
Full Idea: If essence is conceived in terms of modality and the laws of nature are metaphysically necessary, it seems that the laws of nature constitute essentialist knowledge, so the discovery of essences is mostly due to scientists. | |
From: Tuomas E. Tahko (The Epistemology of Essence (draft) [2013], 2.1) | |
A reaction: This seems muddled to me. The idea that the laws themselves are essences is way off target. No one thinks all knowledge of necessities is essentialist. Mumford, for example, doesn't even believe in laws. |