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22593 | Our sensation of light may not be the same as what produces the sensation |
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. |
16569 | The Hot, Cold, Wet and Dry of the philosophers need themselves to be explained |
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' |
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. |