8 ideas
22593 | Our sensation of light may not be the same as what produces the sensation [Descartes] |
Full Idea: There can be a difference between our sensation of light and what is in the objects that produce that sensation in us. | |
From: René Descartes (The World [1631]), quoted by Ian Dunt - How to be a Liberal 1 | |
A reaction: Note only that they 'may' differ, and that he does not assert that they are entirely different. Secondary qualities give information, and are not just mental events. |
8840 | There are five possible responses to the problem of infinite regress in justification [Cleve] |
Full Idea: Sceptics respond to the regress problem by denying knowledge; Foundationalists accept justifications without reasons; Positists say reasons terminate is mere posits; Coherentists say mutual support is justification; Infinitists accept the regress. | |
From: James Van Cleve (Why coherence is not enough [2005], I) | |
A reaction: A nice map of the territory. The doubts of Scepticism are not strong enough for anyone to embrace the view; Foundationalist destroy knowledge (?), as do Positists; Infinitism is a version of Coherentism - which is the winner. |
8841 | Modern foundationalists say basic beliefs are fallible, and coherence is relevant [Cleve] |
Full Idea: Contemporary foundationalists are seldom of the strong Cartesian variety: they do not insist that basic beliefs be absolutely certain. They also tend to allow that coherence can enhance justification. | |
From: James Van Cleve (Why coherence is not enough [2005], III) | |
A reaction: It strikes me that they have got onto a slippery slope. How certain are the basic beliefs? How do you evaluate their certainty? Could incoherence in their implications undermine them? Skyscrapers need perfect foundations. |
16569 | The Hot, Cold, Wet and Dry of the philosophers need themselves to be explained [Descartes] |
Full Idea: If you find it strange that in explaining these elements I do not use the qualities called Hot, Cold, Wet and Dry - as the philosophers do - I shall say to you that these qualities themselves seem to me to need explanation. | |
From: René Descartes (The World [1631], 9:25-6), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 1.3 | |
A reaction: Nice. I take pushing the boundaries of explanation back (or down) to be the basic driving force of all human thought, in metaphysics as well as in physics. |
20964 | Descartes said there was conservation of 'quantity of motion' [Descartes, by Papineau] |
Full Idea: Descartes incorporated the conservation of what he called 'quantity of motion', by which he meant mass times speed. | |
From: report of René Descartes (The World [1631]) by David Papineau - Thinking about Consciousness App 2 | |
A reaction: Mass times velocity is now called 'momentum'. Is this the first ever conservation law? There are now lots of them. |
21731 | Fields can be 'scalar', or 'vector', or 'tensor', or 'spinor' [Baggott] |
Full Idea: Fields can be 'scalar', with no particular direction (pointing, but not pushing or pulling); or 'vector', with a direction (like magnetism, or Newtonian gravity); or 'tensor' (needing further parameters); or 'spinor' (depending on spin orientation). | |
From: Jim Baggott (Farewell to Reality: fairytale physics [2013], 2 'Quantum') | |
A reaction: [compressed] So the question is, why do they differ? What is it in the nature of each field the result in a distinctive directional feature? |
21730 | A 'field' is a property with a magnitude, distributed across all of space and time [Baggott] |
Full Idea: A 'field' is defined in terms of the magnitude of some physical property distributed over every point in time and space. | |
From: Jim Baggott (Farewell to Reality: fairytale physics [2013], 2 'Quantum') | |
A reaction: If it involves a 'property', normal usage entails that there is some entity which possesses the property. So what's the entity? Eh? Eh? You don't know! Disappointed... |
21732 | The current standard model requires 61 particles [Baggott] |
Full Idea: The current model requires 61 particles: three generations of two leptons and two flavours of quark, in three different colours (making 24); the anti-particles of all of these (48); 12 force particles (photon, W1, Z0, 8 gluons), and a Higgs boson. | |
From: Jim Baggott (Farewell to Reality: fairytale physics [2013], 6 n) |