Combining Texts

All the ideas for 'fragments/reports', 'Preface to 'Principles of Philosophy'' and 'Review of Frege's 'Grundlagen''

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6 ideas

1. Philosophy / E. Nature of Metaphysics / 4. Metaphysics as Science
Metaphysics is the roots of the tree of science [Descartes]
     Full Idea: The whole of philosophy is like a tree. The roots are metaphysics, the trunk is physics, and the branches emerging from the trunk are all the other sciences.
     From: René Descartes (Preface to 'Principles of Philosophy' [1647]), quoted by A.W. Moore - The Evolution of Modern Metaphysics 01.2
     A reaction: If Descartes had not believed this he would not have bothered with metaphysics, and philosophy might have been dead by 1650.
2. Reason / F. Fallacies / 4. Circularity
I know the truth that God exists and is the author of truth [Descartes]
     Full Idea: I have very clearly deduced the following truths, that there is a God who is the author of all that is in the world, and who is the source of all truth.
     From: René Descartes (Preface to 'Principles of Philosophy' [1647], p.180)
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / c. Fregean numbers
The 'extension of a concept' in general may be quantitatively completely indeterminate [Cantor]
     Full Idea: The author entirely overlooks the fact that the 'extension of a concept' in general may be quantitatively completely indeterminate. Only in certain cases is the 'extension of a concept' quantitatively determinate.
     From: George Cantor (Review of Frege's 'Grundlagen' [1885], 1932:440), quoted by William W. Tait - Frege versus Cantor and Dedekind
     A reaction: Cantor presumably has in mind various infinite sets. Tait is drawing our attention to the fact that this objection long precedes Russell's paradox, which made the objection more formal (a language Frege could understand!).
11. Knowledge Aims / B. Certain Knowledge / 1. Certainty
Understanding, not the senses, gives certainty [Descartes]
     Full Idea: Certainty is not in the sense but in the understanding alone, when it has evident perceptions.
     From: René Descartes (Preface to 'Principles of Philosophy' [1647], p.177)
21. Aesthetics / C. Artistic Issues / 7. Art and Morality
Musical performance can reveal a range of virtues [Damon of Ath.]
     Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice.
     From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where?
28. God / C. Attitudes to God / 5. Atheism
Atheism arises from empiricism, because God is intangible [Descartes]
     Full Idea: The existence of God has been doubted by some, because they attributed too much to the perceptions of the senses, and God can be neither seen nor touched.
     From: René Descartes (Preface to 'Principles of Philosophy' [1647], p.180)