Combining Texts

All the ideas for 'fragments/reports', 'On the Heavens' and 'A Completeness Theorem in Modal Logic'

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18 ideas

2. Reason / A. Nature of Reason / 9. Limits of Reason
A very hungry man cannot choose between equidistant piles of food [Aristotle]
4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
Propositional modal logic has been proved to be complete [Kripke, by Feferman/Feferman]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / a. Systems of modal logic
With possible worlds, S4 and S5 are sound and complete, but S1-S3 are not even sound [Kripke, by Rossberg]
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
The variable domain approach to quantified modal logic invalidates the Barcan Formula [Kripke, by Simchen]
The Barcan formulas fail in models with varying domains [Kripke, by Williamson]
22. Metaethics / B. Value / 2. Values / b. Successful function
Each thing that has a function is for the sake of that function [Aristotle]
25. Social Practice / E. Policies / 5. Education / b. Education principles
Learned men gain more in one day than others do in a lifetime [Posidonius]
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 / D. Time / 1. Nature of Time / d. Time as measure
Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus]
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]