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All the ideas for 'Theory of Knowledge (2nd edn)', 'works' and 'An Analysis of Knowledge and Valuation'

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9 ideas

1. Philosophy / C. History of Philosophy / 4. Later European Philosophy / b. Seventeenth century philosophy
2945 Most philosophers start with reality and then examine knowledge; Descartes put the study of knowledge first [Lehrer]
     Full Idea: Some philosophers (e.g Plato) begin with an account of reality, and then appended an account of how we can know it, ..but Descartes turned the tables, insisting that we must first decide what we can know.
     From: Keith Lehrer (Theory of Knowledge (2nd edn) [2000], I p.2)
1. Philosophy / F. Analytic Philosophy / 4. Conceptual Analysis
2946 You cannot demand an analysis of a concept without knowing the purpose of the analysis [Lehrer]
     Full Idea: An analysis is always relative to some objective. It makes no sense to simply demand an analysis of goodness, knowledge, beauty or truth, without some indication of the purpose of the analysis.
     From: Keith Lehrer (Theory of Knowledge (2nd edn) [2000], I p.7)
     A reaction: Your dismantling of a car will go better if you know what a car is for, but you can still take it apart in ignorance.
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
21500 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?
21501 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
6556 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
21498 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
5828 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?
27. Natural Reality / A. Classical Physics / 2. Thermodynamics / b. Heat
20645 Heat is a state of vibration, not a substance [Joule]
     Full Idea: We consider heat not as a substance but as a state of vibration.
     From: James Joule (works [1870]), quoted by Peter Watson - Convergence 01 'Nature's'
     A reaction: The puzzle is that giving accurate accounts of vibrations, heat and movement require a quantitative substance, energy. But all we have here is movement, and the denial of a substance. Energy is 'nature's currency system'.
20972 Joule showed that energy converts to heat, and heat to energy [Joule, by Papineau]
     Full Idea: James Joule established the equivalence of heat and mechanical energy, in the sense of showing that a specific amount of heat will always be produced by the expenditure of a given amount of energy, and vice versa.
     From: report of James Joule (works [1870]) by David Papineau - Thinking about Consciousness App 4.2
     A reaction: This was a major step towards the law of conservation of energy.