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All the ideas for 'Lectures on the History of Philosophy', 'The Theory of Knowledge' and 'Grundgesetze der Arithmetik 2 (Basic Laws)'

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17 ideas

1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
Philosophy is the conceptual essence of the shape of history [Hegel]
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]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
Logical constants seem to be entities in propositions, but are actually pure form [Russell]
We use logical notions, so they must be objects - but I don't know what they really are [Russell]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
Logical truths are known by their extreme generality [Russell]
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 / D. Theories of Reality / 8. Facts / d. Negative facts
There can't be a negative of a complex, which is negated by its non-existence [Potter on Russell]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
The first demand of logic is of a sharp boundary [Frege]
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]