Combining Texts

All the ideas for 'The Nature of Things', 'The Laws of Thought' and 'On the Heavens'

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22 ideas

2. Reason / A. Nature of Reason / 9. Limits of Reason
19740 A very hungry man cannot choose between equidistant piles of food [Aristotle]
4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
8083 Boole applied normal algebra to logic, aiming at an algebra of thought [Boole, by Devlin]
7727 Boole's notation can represent syllogisms and propositional arguments, but not both at once [Boole, by Weiner]
4. Formal Logic / F. Set Theory ST / 7. Natural Sets
9406 A class is natural when everybody can spot further members of it [Quinton]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
8686 Boole made logic more mathematical, with algebra, quantifiers and probability [Boole, by Friend]
5. Theory of Logic / H. Proof Systems / 2. Axiomatic Proof
22277 Boole's method was axiomatic, achieving economy, plus multiple interpretations [Boole, by Potter]
7. Existence / E. Categories / 5. Category Anti-Realism
15730 Extreme nominalists say all classification is arbitrary convention [Quinton]
8. Modes of Existence / B. Properties / 5. Natural Properties
15728 The naturalness of a class depends as much on the observers as on the objects [Quinton]
9407 Properties imply natural classes which can be picked out by everybody [Quinton]
8. Modes of Existence / D. Universals / 4. Uninstantiated Universals
15729 Uninstantiated properties must be defined using the instantiated ones [Quinton]
9. Objects / A. Existence of Objects / 5. Individuation / b. Individuation by properties
8520 An individual is a union of a group of qualities and a position [Quinton, by Campbell,K]
22. Metaethics / B. Value / 2. Values / b. Successful function
398 Each thing that has a function is for the sake of that function [Aristotle]
26. Natural Theory / A. Speculations on Nature / 2. Natural Purpose / a. Final purpose
394 An unworn sandal is in vain, but nothing in nature is in vain [Aristotle]
396 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
16102 Aether moves in circles and is imperishable; the four elements perish, and move in straight lines [Aristotle, by Gill,ML]
17463 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
399 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
20918 Void is a kind of place, so it can't explain place [Aristotle]
27. Natural Reality / E. Cosmology / 1. Cosmology
402 The Earth must be spherical, because it casts a convex shadow on the moon [Aristotle]
403 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
1498 Everyone agrees that the world had a beginning, but thinkers disagree over whether it will end [Aristotle]
27. Natural Reality / E. Cosmology / 10. Multiverse
395 It seems possible that there exists a limited number of other worlds apart from this one [Aristotle]