Combining Texts

All the ideas for '67: Platonic Questions', 'Grundgesetze der Arithmetik 2 (Basic Laws)' and 'Fourfold Root of Princ of Sufficient Reason'

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21 ideas

2. Reason / B. Laws of Thought / 2. Sufficient Reason
Sufficient Reason can't be proved, because all proof presupposes it [Schopenhauer, by Lewis,PB]
2. Reason / D. Definition / 2. Aims of Definition
Later Frege held that definitions must fix a function's value for every possible argument [Frege, by Wright,C]
2. Reason / D. Definition / 7. Contextual Definition
We can't define a word by defining an expression containing it, as the remaining parts are a problem [Frege]
2. Reason / D. Definition / 11. Ostensive Definition
Only what is logically complex can be defined; what is simple must be pointed to [Frege]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
Cardinals say how many, and reals give measurements compared to a unit quantity [Frege]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
Real numbers are ratios of quantities [Frege, by Dummett]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / c. Fregean numbers
A number is a class of classes of the same cardinality [Frege, by Dummett]
Frege's biggest error is in not accounting for the senses of number terms [Hodes on Frege]
6. Mathematics / C. Sources of Mathematics / 7. Formalism
Formalism misunderstands applications, metatheory, and infinity [Frege, by Dummett]
Only applicability raises arithmetic from a game to a science [Frege]
7. Existence / E. Categories / 1. Categories
No need for a priori categories, since sufficient reason shows the interrelations [Schopenhauer, by Lewis,PB]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
The first demand of logic is of a sharp boundary [Frege]
10. Modality / A. Necessity / 3. Types of Necessity
Necessity is physical, logical, mathematical or moral [Schopenhauer, by Janaway]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / a. Idealism
For Schopenhauer, material things would not exist without the mind [Schopenhauer, by Janaway]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / b. Transcendental idealism
Object for a subject and representation are the same thing [Schopenhauer]
14. Science / D. Explanation / 2. Types of Explanation / a. Types of explanation
The four explanations: objects by causes, concepts by ground, maths by spacetime, ethics by motive [Schopenhauer, by Lewis,PB]
15. Nature of Minds / A. Nature of Mind / 2. Psuche
When the soul is intelligent and harmonious, it is part of god and derives from god [Plutarch]
18. Thought / D. Concepts / 2. Origin of Concepts / b. Empirical concepts
Concepts are abstracted from perceptions [Schopenhauer, by Lewis,PB]
18. Thought / E. Abstraction / 3. Abstracta by Ignoring
The modern account of real numbers detaches a ratio from its geometrical origins [Frege]
18. Thought / E. Abstraction / 8. Abstractionism Critique
If we abstract the difference between two houses, they don't become the same house [Frege]
20. Action / C. Motives for Action / 3. Acting on Reason / c. Reasons as causes
Motivation is causality seen from within [Schopenhauer]