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All the ideas for 'fragments/reports', 'Logical Properties' and 'Begriffsschrift'

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61 ideas

1. Philosophy / F. Analytic Philosophy / 6. Logical Analysis
Frege changed philosophy by extending logic's ability to check the grounds of thinking [Potter on Frege]
2. Reason / B. Laws of Thought / 1. Laws of Thought
We should not describe human laws of thought, but how to correctly track truth [Frege, by Fisher]
2. Reason / D. Definition / 1. Definitions
Definitions identify two concepts, so they presuppose identity [McGinn]
2. Reason / F. Fallacies / 2. Infinite Regress
Regresses are only vicious in the context of an explanation [McGinn]
3. Truth / A. Truth Problems / 4. Uses of Truth
Truth is a method of deducing facts from propositions [McGinn]
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
'Snow does not fall' corresponds to snow does fall [McGinn]
The idea of truth is built into the idea of correspondence [McGinn]
3. Truth / D. Coherence Truth / 2. Coherence Truth Critique
The coherence theory of truth implies idealism, because facts are just coherent beliefs [McGinn]
3. Truth / H. Deflationary Truth / 3. Minimalist Truth
Truth is the property of propositions that makes it possible to deduce facts [McGinn]
Without the disquotation device for truth, you could never form beliefs from others' testimony [McGinn]
4. Formal Logic / C. Predicate Calculus PC / 1. Predicate Calculus PC
I don't use 'subject' and 'predicate' in my way of representing a judgement [Frege]
4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / d. Universal quantifier ∀
For Frege, 'All A's are B's' means that the concept A implies the concept B [Frege, by Walicki]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Frege has a judgement stroke (vertical, asserting or judging) and a content stroke (horizontal, expressing) [Frege, by Weiner]
The laws of logic are boundless, so we want the few whose power contains the others [Frege]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
In 1879 Frege developed second order logic [Frege, by Putnam]
5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic
In 'x is F and x is G' we must assume the identity of x in the two statements [McGinn]
Both non-contradiction and excluded middle need identity in their formulation [McGinn]
Identity is unitary, indefinable, fundamental and a genuine relation [McGinn]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Frege replaced Aristotle's subject/predicate form with function/argument form [Frege, by Weiner]
5. Theory of Logic / G. Quantification / 1. Quantification
A quantifier is a second-level predicate (which explains how it contributes to truth-conditions) [Frege, by George/Velleman]
Existential quantifiers just express the quantity of things, leaving existence to the predicate 'exists' [McGinn]
The quantifier is overrated as an analytical tool [McGinn]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
For Frege the variable ranges over all objects [Frege, by Tait]
Frege's domain for variables is all objects, but modern interpretations first fix the domain [Dummett on Frege]
5. Theory of Logic / G. Quantification / 3. Objectual Quantification
Frege introduced quantifiers for generality [Frege, by Weiner]
Frege reduced most quantifiers to 'everything' combined with 'not' [Frege, by McCullogh]
'Partial quantifier' would be a better name than 'existential quantifier', as no existence would be implied [McGinn]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
We need an Intentional Quantifier ("some of the things we talk about.."), so existence goes into the proposition [McGinn]
5. Theory of Logic / H. Proof Systems / 1. Proof Systems
Proof theory began with Frege's definition of derivability [Frege, by Prawitz]
5. Theory of Logic / H. Proof Systems / 2. Axiomatic Proof
Frege produced axioms for logic, though that does not now seem the natural basis for logic [Frege, by Kaplan]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / f. Mathematical induction
It may be possible to define induction in terms of the ancestral relation [Frege, by Wright,C]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
Frege's logic has a hierarchy of object, property, property-of-property etc. [Frege, by Smith,P]
7. Existence / A. Nature of Existence / 1. Nature of Existence
Existence is a primary quality, non-existence a secondary quality [McGinn]
Existence is not a first-order property, but the instantiation of a property [Frege, by Read]
7. Existence / A. Nature of Existence / 6. Criterion for Existence
Existence can't be analysed as instantiating a property, as instantiation requires existence [McGinn]
We can't analyse the sentence 'something exists' in terms of instantiated properties [McGinn]
7. Existence / D. Theories of Reality / 3. Reality
If causal power is the test for reality, that will exclude necessities and possibilities [McGinn]
7. Existence / D. Theories of Reality / 8. Facts / b. Types of fact
Facts are object-plus-extension, or property-plus-set-of-properties, or object-plus-property [McGinn]
9. Objects / F. Identity among Objects / 1. Concept of Identity
Identity propositions are not always tautological, and have a key epistemic role [McGinn]
9. Objects / F. Identity among Objects / 2. Defining Identity
Identity is as basic as any concept could ever be [McGinn]
9. Objects / F. Identity among Objects / 4. Type Identity
Type-identity is close similarity in qualities [McGinn]
It is best to drop types of identity, and speak of 'identity' or 'resemblance' [McGinn]
Qualitative identity is really numerical identity of properties [McGinn]
Qualitative identity can be analysed into numerical identity of the type involved [McGinn]
9. Objects / F. Identity among Objects / 5. Self-Identity
Sherlock Holmes does not exist, but he is self-identical [McGinn]
Existence is a property of all objects, but less universal than self-identity, which covers even conceivable objects [McGinn]
9. Objects / F. Identity among Objects / 6. Identity between Objects
All identity is necessary, though identity statements can be contingently true [McGinn]
9. Objects / F. Identity among Objects / 8. Leibniz's Law
Leibniz's Law presupposes the notion of property identity [McGinn]
Leibniz's Law says 'x = y iff for all P, Px iff Py' [McGinn]
Leibniz's Law is so fundamental that it almost defines the concept of identity [McGinn]
10. Modality / C. Sources of Modality / 5. Modality from Actuality
Modality is not objects or properties, but the type of binding of objects to properties [McGinn]
10. Modality / E. Possible worlds / 1. Possible Worlds / b. Impossible worlds
If 'possible' is explained as quantification across worlds, there must be possible worlds [McGinn]
12. Knowledge Sources / D. Empiricism / 5. Empiricism Critique
Necessity and possibility are big threats to the empiricist view of knowledge [McGinn]
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
Scepticism about reality is possible because existence isn't part of appearances [McGinn]
19. Language / C. Assigning Meanings / 4. Compositionality
Frege's account was top-down and decompositional, not bottom-up and compositional [Frege, by Potter]
19. Language / C. Assigning Meanings / 5. Fregean Semantics
Semantics should not be based on set-membership, but on instantiation of properties in objects [McGinn]
19. Language / C. Assigning Meanings / 7. Extensional Semantics
Clearly predicates have extensions (applicable objects), but are the extensions part of their meaning? [McGinn]
21. Aesthetics / C. Artistic Issues / 7. Art and Morality
Musical performance can reveal a range of virtues [Damon of Ath.]
28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique
The predicate 'exists' is actually a natural language expression for a quantifier [Frege, by Weiner]
If Satan is the most imperfect conceivable being, he must have non-existence [McGinn]
I think the fault of the Ontological Argument is taking the original idea to be well-defined [McGinn]