Combining Texts

All the ideas for 'fragments/reports', 'An Analysis of Knowledge and Valuation' and 'The World'

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10 ideas

12. Knowledge Sources / B. Perception / 2. Qualities in Perception / d. Secondary qualities
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.
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
We rely on memory for empirical beliefs because they mutually support one another [Lewis,CI]
     Full Idea: When the whole range of empirical beliefs is taken into account, all of them more or less dependent on memorial knowledge, we find that those which are most credible can be assured by their mutual support, or 'congruence'.
     From: C.I. Lewis (An Analysis of Knowledge and Valuation [1946], 334), quoted by Erik J. Olsson - Against Coherence 3.1
     A reaction: Lewis may be over-confident about this, and is duly attacked by Olson, but it seems to me roughly correct. How do you assess whether some unusual element in your memory was a dream or a real experience?
If we doubt memories we cannot assess our doubt, or what is being doubted [Lewis,CI]
     Full Idea: To doubt our sense of past experience as founded in actuality, would be to lose any criterion by which either the doubt itself or what is doubted could be corroborated.
     From: C.I. Lewis (An Analysis of Knowledge and Valuation [1946], 358), quoted by Erik J. Olsson - Against Coherence 3.3.1
     A reaction: Obviously scepticism about memory can come in degrees, but total rejection of short-term and clear memories looks like a non-starter. What could you put in its place? Hyper-rationalism? Even maths needs memory.
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / a. Foundationalism
If anything is to be probable, then something must be certain [Lewis,CI]
     Full Idea: If anything is to be probable, then something must be certain.
     From: C.I. Lewis (An Analysis of Knowledge and Valuation [1946], 186), quoted by Robert Fogelin - Walking the Tightrope of Reason Intro
     A reaction: Lewis makes this comment when facing infinite regress problems. It is a very nice slogan for foundationalism, which embodies the slippery slope view. Personally I feel the emotional pull of foundations, but acknowledge the very strong doubts about them.
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / b. Pro-coherentism
Congruents assertions increase the probability of each individual assertion in the set [Lewis,CI]
     Full Idea: A set of statements, or a set of supposed facts asserted, will be said to be congruent if and only if they are so related that the antecedent probability of any one of them will be increased if the remainder of the set can be assumed as given premises.
     From: C.I. Lewis (An Analysis of Knowledge and Valuation [1946], 338), quoted by Erik J. Olsson - Against Coherence 2.2
     A reaction: This thesis is vigorously attacked by Erik Olson, who works through the probability calculations. There seems an obvious problem without that. How else do you assess 'congruence', other than by evidence of mutual strengthening?
18. Thought / C. Content / 8. Intension
Extension is the class of things, intension is the correct definition of the thing, and intension determines extension [Lewis,CI]
     Full Idea: "The denotation or extension of a term is the class of all actual or existent things which the term correctly applies to or names; the connotation or intension of a term is delimited by any correct definition of it." ..And intension determines extension.
     From: C.I. Lewis (An Analysis of Knowledge and Valuation [1946]), quoted by Stephen P. Schwartz - Intro to Naming,Necessity and Natural Kinds §II
     A reaction: The last part is one of the big ideas in philosophy of language, which was rejected by Putnam and co. If you were to reverse the slogan, though, (to extension determines intension) how would you identify the members of the extension?
25. Social Practice / E. Policies / 5. Education / b. Education principles
Learned men gain more in one day than others do in a lifetime [Posidonius]
     Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes.
     From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078
     A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book.
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / f. Ancient elements
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.
27. Natural Reality / A. Classical Physics / 1. Mechanics / b. Laws of motion
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.
27. Natural Reality / D. Time / 1. Nature of Time / d. Time as measure
Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus]
     Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness.
     From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42
     A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them.