Combining Texts

All the ideas for 'Symposium', 'Letters to Russell' and 'Fifteen Sermons'

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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.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / c. Ethical intuitionism
Butler exalts conscience, but it may be horribly misleading [Anscombe on Butler]
     Full Idea: Butler exalts conscience, but appears ignorant that a man's conscience may tell him to do the vilest things.
     From: comment on Joseph Butler (Fifteen Sermons [1726]) by G.E.M. Anscombe - Modern Moral Philosophy p.176
     A reaction: That would appear to be the end of conscience. To make conscience work, it must have a huge authority to back it, and also a fairly infallible means of knowing what it truly says, and that an impostor hasn't replaced it (e.g. via a bad upbringing).
22. Metaethics / B. Value / 2. Values / h. Fine deeds
Niceratus learnt the whole of Homer by heart, as a guide to goodness [Xenophon]
     Full Idea: Niceratus said that his father, because he was concerned to make him a good man, made him learn the whole works of Homer, and he could still repeat by heart the entire 'Iliad' and 'Odyssey'.
     From: Xenophon (Symposium [c.391 BCE], 3.5)
     A reaction: This clearly shows the status which Homer had in the teaching of morality in the time of Socrates, and it is precisely this acceptance of authority which he was challenging, in his attempts to analyse the true basis of virtue