Combining Philosophers

All the ideas for Hermarchus, Euclid and Jeff McMahan

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36 ideas

2. Reason / E. Argument / 6. Conclusive Proof
Proof reveals the interdependence of truths, as well as showing their certainty [Euclid, by Frege]
4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / c. Derivations rules of PC
If you pick an arbitrary triangle, things proved of it are true of all triangles [Euclid, by Lemmon]
6. Mathematics / A. Nature of Mathematics / 2. Geometry
Euclid's geometry is synthetic, but Descartes produced an analytic version of it [Euclid, by Resnik]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
An assumption that there is a largest prime leads to a contradiction [Euclid, by Brown,JR]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / m. One
A unit is that according to which each existing thing is said to be one [Euclid]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Postulate 2 says a line can be extended continuously [Euclid, by Shapiro]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
Euclid relied on obvious properties in diagrams, as well as on his axioms [Potter on Euclid]
Euclid's parallel postulate defines unique non-intersecting parallel lines [Euclid, by Friend]
Euclid needs a principle of continuity, saying some lines must intersect [Shapiro on Euclid]
Euclid says we can 'join' two points, but Hilbert says the straight line 'exists' [Euclid, by Bernays]
Modern geometries only accept various parts of the Euclid propositions [Russell on Euclid]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / b. Greek arithmetic
Euclid's common notions or axioms are what we must have if we are to learn anything at all [Euclid, by Roochnik]
20. Action / C. Motives for Action / 4. Responsibility for Actions
Legal excuses are duress, ignorance, and diminished responsibility [McMahan]
25. Social Practice / C. Rights / 1. Basis of Rights
Liberty Rights are permissions, and Claim Rights are freedom from intervention [McMahan]
25. Social Practice / E. Policies / 1. War / a. Just wars
The worst unjustified wars have no aim at all [McMahan]
A defensive war is unjust, if it is responding to a just war [McMahan]
A person or state may be attacked if they are responsible for an unjustified threat [McMahan]
You (e.g. a police officer) are not liable to attack just because you pose a threat [McMahan]
Wars can be unjust, despite a just cause, if they are unnecessary or excessive or of mixed cause [McMahan]
Just war theory says all and only persons posing a threat are liable to attack [McMahan]
25. Social Practice / E. Policies / 1. War / b. Justice in war
Proportionality in fighting can't be judged independently of the justice of each side [McMahan]
Can an army start an unjust war, and then fight justly to defend their own civilians? [McMahan]
Soldiers cannot freely fight in unjust wars, just because they behave well when fighting [McMahan]
The law of war differs from criminal law; attacking just combatants is immoral, but legal [McMahan]
If the unjust combatants are morally excused they are innocent, so how can they be killed? [McMahan]
25. Social Practice / E. Policies / 1. War / c. Combatants
You don't become a legitimate target, just because you violently resist an unjust attack [McMahan]
If all combatants are seen as morally equal, that facilitates starting unjust wars [McMahan]
Volunteer soldiers accept the risk of attack, but they don't agree to it, or to their deaths [McMahan]
If being part of a big collective relieves soldiers of moral responsibility, why not the leaders too? [McMahan]
If soldiers can't refuse to fight in unjust wars, can they choose to fight in just wars? [McMahan]
Equality is both sides have permission, or both sides are justified, or one justified the other permitted [McMahan]
Fighting unjustly under duress does not justify it, or permit it, but it may excuse it [McMahan]
Soldiers cannot know enough facts to evaluate the justice of their war [McMahan]
25. Social Practice / E. Policies / 1. War / d. Non-combatants
Innocence implies not being morally responsible, rather than merely being guiltless [McMahan]
25. Social Practice / E. Policies / 1. War / e. Peace
Unconditional surrender can't be demanded, since evil losers still have legitimate conditions [McMahan]
25. Social Practice / F. Life Issues / 6. Animal Rights
Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley]