Combining Texts

All the ideas for 'Taking Rights Seriously', 'On the Heavens' and 'Begriffsschrift'

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35 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 / A. Nature of Reason / 9. Limits of Reason
A very hungry man cannot choose between equidistant piles of food [Aristotle]
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]
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 / 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]
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]
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 not a first-order property, but the instantiation of a property [Frege, by Read]
19. Language / C. Assigning Meanings / 4. Compositionality
Frege's account was top-down and decompositional, not bottom-up and compositional [Frege, by Potter]
22. Metaethics / B. Value / 2. Values / b. Successful function
Each thing that has a function is for the sake of that function [Aristotle]
24. Political Theory / D. Ideologies / 6. Liberalism / b. Liberal individualism
Dworkin believed we should promote equality, to increase autonomy [Dworkin, by Kekes]
25. Social Practice / B. Equalities / 1. Grounds of equality
We can treat people as equals, or actually treat them equally [Dworkin, by Grayling]
Treating people as equals is the one basic value of all plausible political theories [Dworkin, by Kymlicka]
26. Natural Theory / A. Speculations on Nature / 2. Natural Purpose / a. Final purpose
An unworn sandal is in vain, but nothing in nature is in vain [Aristotle]
There has to be some goal, and not just movement to infinity [Aristotle]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / f. Ancient elements
Aether moves in circles and is imperishable; the four elements perish, and move in straight lines [Aristotle, by Gill,ML]
An element is what bodies are analysed into, and won't itself divide into something else [Aristotle]
27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
If the more you raise some earth the faster it moves, why does the whole earth not move? [Aristotle]
27. Natural Reality / C. Space / 1. Void
Void is a kind of place, so it can't explain place [Aristotle]
27. Natural Reality / E. Cosmology / 1. Cosmology
The Earth must be spherical, because it casts a convex shadow on the moon [Aristotle]
The earth must be round and of limited size, because moving north or south makes different stars visible [Aristotle]
27. Natural Reality / E. Cosmology / 3. The Beginning
Everyone agrees that the world had a beginning, but thinkers disagree over whether it will end [Aristotle]
27. Natural Reality / E. Cosmology / 10. Multiverse
It seems possible that there exists a limited number of other worlds apart from this one [Aristotle]
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]