Combining Texts

All the ideas for 'Mahaprajnaparamitashastra', 'Letters to Russell' and 'Metaphysical Foundations of Mathematics'

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5 ideas

6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
I wish to go straight from cardinals to reals (as ratios), leaving out the rationals [Frege]
     Full Idea: You need a double transition, from cardinal numbes (Anzahlen) to the rational numbers, and from the latter to the real numbers generally. I wish to go straight from the cardinal numbers to the real numbers as ratios of quantities.
     From: Gottlob Frege (Letters to Russell [1902], 1903.05.21), quoted by Michael Dummett - Frege philosophy of mathematics 21 'Frege's'
     A reaction: Note that Frege's real numbers are not quantities, but ratios of quantities. In this way the same real number can refer to lengths, masses, intensities etc.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
The loss of my Rule V seems to make foundations for arithmetic impossible [Frege]
     Full Idea: With the loss of my Rule V, not only the foundations of arithmetic, but also the sole possible foundations of arithmetic, seem to vanish.
     From: Gottlob Frege (Letters to Russell [1902], 1902.06.22)
     A reaction: Obviously he was stressed, but did he really mean that there could be no foundation for arithmetic, suggesting that the subject might vanish into thin air?
9. Objects / A. Existence of Objects / 2. Abstract Objects / c. Modern abstracta
Logical objects are extensions of concepts, or ranges of values of functions [Frege]
     Full Idea: How are we to conceive of logical objects? My only answer is, we conceive of them as extensions of concepts or, more generally, as ranges of values of functions ...what other way is there?
     From: Gottlob Frege (Letters to Russell [1902], 1902.07.28), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 7 epigr
     A reaction: This is the clearest statement I have found of what Frege means by an 'object'. But an extension is a collection of things, so an object is a group treated as a unity, which is generally how we understand a 'set'. Hence Quine's ontology.
23. Ethics / C. Virtue Theory / 3. Virtues / a. Virtues
The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna]
     Full Idea: The six perfections are of giving, morality, patience, vigour, meditation, and wisdom.
     From: Nagarjuna (Mahaprajnaparamitashastra [c.120], 88)
     A reaction: What is 'morality', if giving is not part of it? I like patience and vigour being two of the virtues, which immediately implies an Aristotelian mean (which is always what is 'appropriate').
27. Natural Reality / D. Time / 2. Passage of Time / g. Time's arrow
When one element contains the grounds of the other, the first one is prior in time [Leibniz]
     Full Idea: When one of two non-contemporaneous elements contains the grounds for the other, the former is regarded as the antecedent, and the latter as the consequence
     From: Gottfried Leibniz (Metaphysical Foundations of Mathematics [1715], p.201)
     A reaction: Bardon cites this passage of Leibniz as the origin of the idea that time's arrow is explained by the direction of causation. Bardon prefers it to the psychological and entropy accounts.