Combining Texts

All the ideas for 'Natural Kinds and Biological Realism', 'An Analysis of Knowledge and Valuation' and 'Letters to Antoine Arnauld'

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9 ideas

6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
It is possible that an omnipotent God might make one and two fail to equal three [Descartes]
     Full Idea: Since every basic truth depends on God's omnipotence, I would not dare to say that God cannot make it....that one and two should not be three.
     From: René Descartes (Letters to Antoine Arnauld [1645]), quoted by A.W. Moore - The Evolution of Modern Metaphysics 01.3
     A reaction: An unusual view. Most people would say that if Descartes can doubt something that simple, he should also doubt his reasons for believing in God's existence.
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?
26. Natural Theory / B. Natural Kinds / 1. Natural Kinds
Some kinds are very explanatory, but others less so, and some not at all [Devitt]
     Full Idea: Explanatory significance, hence naturalness, comes in degrees: positing some kinds may be very explanatory, positing others, only a little bit explanatory, positing others still, not explanatory at all.
     From: Michael Devitt (Natural Kinds and Biological Realism [2009], 4)
     A reaction: He mentions 'cousin' as a natural kind that is not very explanatory of anything. It interests us as humans, but not at all in other animals, it seems. ...Nice thought, though, that two squirrels might be cousins...
27. Natural Reality / G. Biology / 5. Species
The higher categories are not natural kinds, so the Linnaean hierarchy should be given up [Devitt]
     Full Idea: The signs are that the higher categories are not natural kinds and so the Linnaean hierarchy must be abandoned. ...This is not abandoning a hierarchy altogether, it is not abandoning a tree of life.
     From: Michael Devitt (Natural Kinds and Biological Realism [2009], 6)
     A reaction: Devitt's underlying point is that the higher and more general kinds do not have an essence (a specific nature), which is the qualification to be a natural kind. They explain nothing. Essence is the hallmark of natural kinds. Hmmm.
Species pluralism says there are several good accounts of what a species is [Devitt]
     Full Idea: Species pluralism is the view that there are several equally good accounts of what it is to be a species.
     From: Michael Devitt (Natural Kinds and Biological Realism [2009], 7)
     A reaction: Devitt votes for it, and cites Dupré, among many other. Given the existence of rival accounts, all making good points, it is hard to resist this view.