Combining Texts

All the ideas for 'fragments/reports', 'Modal Logic' and 'Review of Husserl's 'Phil of Arithmetic''

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23 ideas

2. Reason / D. Definition / 2. Aims of Definition
9821 A definition need not capture the sense of an expression - just get the reference right [Frege, by Dummett]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
9585 Since every definition is an equation, one cannot define equality itself [Frege]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / b. System K
14970 Normal system K has five axioms and rules [Cresswell]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / c. System D
14971 D is valid on every serial frame, but not where there are dead ends [Cresswell]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
14972 S4 has 14 modalities, and always reduces to a maximum of three modal operators [Cresswell]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
14973 In S5 all the long complex modalities reduce to just three, and their negations [Cresswell]
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
14976 Reject the Barcan if quantifiers are confined to worlds, and different things exist in other worlds [Cresswell]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / e. Counting by correlation
17446 Counting rests on one-one correspondence, of numerals to objects [Frege]
9582 Husserl rests sameness of number on one-one correlation, forgetting the correlation with numbers themselves [Frege]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / c. Fregean numbers
9586 In a number-statement, something is predicated of a concept [Frege]
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
9580 Our concepts recognise existing relations, they don't change them [Frege]
9589 Numbers are not real like the sea, but (crucially) they are still objective [Frege]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
9577 The naïve view of number is that it is like a heap of things, or maybe a property of a heap [Frege]
7. Existence / C. Structure of Existence / 7. Abstract/Concrete / b. Levels of abstraction
9578 If objects are just presentation, we get increasing abstraction by ignoring their properties [Frege]
8. Modes of Existence / A. Relations / 4. Formal Relations / a. Types of relation
14974 A relation is 'Euclidean' if aRb and aRc imply bRc [Cresswell]
10. Modality / A. Necessity / 4. De re / De dicto modality
14975 A de dicto necessity is true in all worlds, but not necessarily of the same thing in each world [Cresswell]
10. Modality / A. Necessity / 8. Transcendental Necessity
490 Everything happens by reason and necessity [Leucippus]
18. Thought / A. Modes of Thought / 1. Thought
9581 Many people have the same thought, which is the component, not the private presentation [Frege]
18. Thought / E. Abstraction / 3. Abstracta by Ignoring
9579 Disregarding properties of two cats still leaves different objects, but what is now the difference? [Frege]
9587 How do you find the right level of inattention; you eliminate too many or too few characteristics [Frege]
18. Thought / E. Abstraction / 8. Abstractionism Critique
9588 Number-abstraction somehow makes things identical without changing them! [Frege]
19. Language / A. Nature of Meaning / 2. Meaning as Mental
9583 Psychological logicians are concerned with sense of words, but mathematicians study the reference [Frege]
9584 Identity baffles psychologists, since A and B must be presented differently to identify them [Frege]