40 ideas
| 2098 | The principle of sufficient reason is needed if we are to proceed from maths to physics [Leibniz] |
| Full Idea: In order to proceed from mathematics to physics the principle of sufficient reason is necessary, that nothing happens without there being a reason why it should be thus rather than otherwise. | |
| From: Gottfried Leibniz (Letters to Samuel Clarke [1716], §2) |
| 3646 | There is always a reason why things are thus rather than otherwise [Leibniz] |
| Full Idea: Nothing happens without a sufficient reason why it should be thus rather than otherwise. | |
| From: Gottfried Leibniz (Letters to Samuel Clarke [1716], 3.2) |
| 2104 | No reason could limit the quantity of matter, so there is no limit [Leibniz] |
| Full Idea: There is no possible reason which could limit the quantity of matter; therefore there cannot in fact be any such limitation. | |
| From: Gottfried Leibniz (Letters to Samuel Clarke [1716], 4.21) |
| 19385 | All simply substances are in harmony, because they all represent the one universe [Leibniz] |
| Full Idea: All simple substances will always have a harmony among themselves, because they always represent the same universe. | |
| From: Gottfried Leibniz (Letters to Samuel Clarke [1716], V §91), quoted by Richard T.W. Arthur - Leibniz | |
| A reaction: We can accept that the universe itself does not contain contradictions (how could it), but it is a leap of faith to say that all monads represent the universe well enough to avoid contradictions. Maps can contradict one another. |
| 21346 | The ratio between two lines can't be a feature of one, and cannot be in both [Leibniz] |
| Full Idea: If the ratio of two lines L and M is conceived as abstracted from them both, without considering which is the subject and which the object, which will then be the subject? We cannot say both, for then we should have an accident in two subjects. | |
| From: Gottfried Leibniz (Letters to Samuel Clarke [1716], 5th Paper, §47), quoted by John Heil - Relations 'External' | |
| A reaction: [compressed] Leibniz is rejecting external relations as having any status in ontology. It looks like a mistake (originating in Aristotle) to try to shoehorn the ontology of relations into the substance-properties framework. |
| 23616 | Legal excuses are duress, ignorance, and diminished responsibility [McMahan] |
| Full Idea: The common legal practice is to distinguish three broad categories of excuse: duress, epistemic limitation, and diminished responsibility. | |
| From: Jeff McMahan (Killing in War [2009], 3.2.1) | |
| A reaction: McMahan cites these with reference to soldiers in wartime, but they have general application. The third one seems particularly open to very wide interpretation. Presumably I can't be excused by just being irresponsible. |
| 23606 | Liberty Rights are permissions, and Claim Rights are freedom from intervention [McMahan] |
| Full Idea: There are two types of right. A Liberty right is merely a permission, meaning it is not wrong to do it. But a Claim right is a right against intervention, meaning no one has a liberty right to prevent it. | |
| From: Jeff McMahan (Killing in War [2009], 2.3) | |
| A reaction: There must also be a third type of right, which requires other people to perform actions on your behalf. If you pay for a book in a shop, you must then be given the book. |
| 23595 | The worst unjustified wars have no aim at all [McMahan] |
| Full Idea: The most serious reason why a war might be unjustified is that it lacks any justifying aim at all. | |
| From: Jeff McMahan (Killing in War [2009], 1.1) | |
| A reaction: It seems that Louis XIV invaded the Netherlands in around 1674 purely to enhance his own glory. That strikes me as worse. I supposed Ghenghis Khan invaded places simply because he enjoyed fighting. |
| 23619 | A defensive war is unjust, if it is responding to a just war [McMahan] |
| Full Idea: It is possible for a defensive war to be unjust, when the defensive war to which it is a response is a just war. | |
| From: Jeff McMahan (Killing in War [2009], 3.3.3) | |
| A reaction: An example might be a state resisting an intervention from outside, when the state is in the process of exterminating some unwanted minority. Or perhaps the invaders are crossing the state's territory to achieve some admirable end. |
| 23620 | A person or state may be attacked if they are responsible for an unjustified threat [McMahan] |
| Full Idea: It is a necessary condition of liability to defensive attack that one be morally responsible for posing an objectively unjustified threat. | |
| From: Jeff McMahan (Killing in War [2009], 4.1.1) | |
| A reaction: This implies that one may not actually be doing the threatening (but merely ordering it, or enabling it). McMahan aims to have the same criteria for wartime as for peacetime. He denies Anscombe's claim that merely posing the threat is enough. |
| 23598 | You (e.g. a police officer) are not liable to attack just because you pose a threat [McMahan] |
| Full Idea: It is false that by posing a threat to another, one necessarily makes oneself liable to defensive action. A police officer who shoots an active murderer does not thereby by make herself liable to defensive action. | |
| From: Jeff McMahan (Killing in War [2009], 1.2) | |
| A reaction: This is one of his arguments against the moral equality of combatants. It is not morally OK to shoot all the local soldiers when you unjustly invade a territory. Sounds right to me. |
| 23594 | Wars can be unjust, despite a just cause, if they are unnecessary or excessive or of mixed cause [McMahan] |
| Full Idea: Wars can be unjust despite having a just cause, because they are not actually needed, or they will cause excessive harm, or they also pursue some unjust causes. | |
| From: Jeff McMahan (Killing in War [2009], 1.1) | |
| A reaction: [compressed] The point is that older writers often think that a 'just cause' is sufficient. He is obviously right. |
| 23597 | Just war theory says all and only persons posing a threat are liable to attack [McMahan] |
| Full Idea: In mainstream just war theory (Anscombe, Nagel, Walzer) the criterion of liability to attack is simply posing a threat. Since all combatants pose a threat to each other, they are morally liable to attack; because noncombatants do not, they are not liable. | |
| From: Jeff McMahan (Killing in War [2009], 1.2) | |
| A reaction: McMahan says that the distinction between legitimate and illegitimate targets rests mostly on this basis. The problem is that a huge range of unarmed people can also pose various degrees of threat. |
| 23600 | Proportionality in fighting can't be judged independently of the justice of each side [McMahan] |
| Full Idea: There is simply no satisfactory understanding of proportionality in war that can be applied independently of whether the acts that are evaluated support a just or an unjust cause. | |
| From: Jeff McMahan (Killing in War [2009], 1.3) | |
| A reaction: He rejects traditional just war theory, which sees both sides as morally equal in combat, and hence equally subject to the principles of proportional response. But the just can then be harsher, when their just principles should make them milder. |
| 23603 | Can an army start an unjust war, and then fight justly to defend their own civilians? [McMahan] |
| Full Idea: There is a paradox if the unjust are justified in fighting the just in order to protect their own civilians who have been endangered by the starting of an unjust war. | |
| From: Jeff McMahan (Killing in War [2009], 2.1) | |
| A reaction: [my summary of MacMahan pp.48-49] It suggests that in a war there may be local concepts of justice which are at odds with the general situation - which is the ad bellum/in bello distinction. But this is the justice of fighting, not how it is conducted. |
| 23611 | Soldiers cannot freely fight in unjust wars, just because they behave well when fighting [McMahan] |
| Full Idea: We must stop reassuring soldiers that they act permissibly when they fight in an unjust war, provided that they conduct themselve honorably on the battlefield by fighting in accordance with the rules of engagement. | |
| From: Jeff McMahan (Killing in War [2009], 2.8) | |
| A reaction: This culminates McMahan's arguments against the moral equality of combatants, and against the sharp division of justice of war from justice in war. How rare it is for philosophy to culminate in a policy recommendation! |
| 23612 | The law of war differs from criminal law; attacking just combatants is immoral, but legal [McMahan] |
| Full Idea: Unlike domestic criminal law, the law of war is designed not to protect moral rights but to prevent harm. …This means when unjust combatants attack just combatants they violate their moral rights, yet they act within their legal rights. | |
| From: Jeff McMahan (Killing in War [2009], 3.1.1) | |
| A reaction: He says we must bring the law of war much closer to the morality of war. If there is any hope of slowly eliminating war, it may lie in reforms such as these. |
| 23617 | If the unjust combatants are morally excused they are innocent, so how can they be killed? [McMahan] |
| Full Idea: If most unjust combatants are morally innocent because they are excused, and if it is wrong to intentionally kill morally innocent people, then a contingent form of pacificism may be inescapable. | |
| From: Jeff McMahan (Killing in War [2009], 3.3.1) | |
| A reaction: A very nice argument against the moral equality of combatants. If I think we are the good guys, and the opposing troops are no morally different from us, how can I possibly kill them? |
| 23599 | You don't become a legitimate target, just because you violently resist an unjust attack [McMahan] |
| Full Idea: It is hard to see how just combatants could become legitimate targets simply by offering violent resistance to unjust attacks by unjust coombatants. | |
| From: Jeff McMahan (Killing in War [2009], 1.3) | |
| A reaction: It is, however, hard to criticise a soldier who is dragged into fighting for an unjust cause, and then kills just defenders in the course of the fight. Once the bullets fly, normal morality seems to be suspended. Just survive. |
| 23596 | If all combatants are seen as morally equal, that facilitates starting unjust wars [McMahan] |
| Full Idea: It would be naïve to doubt that the widespread acceptance of the moral equality of combatants has facilitated the ability of governments to fight unjust wars. | |
| From: Jeff McMahan (Killing in War [2009], 1.1) | |
| A reaction: The point is that their armies are both compliant and seeing their actions as guiltless, which makes them perfect tools for evil. McMahan's ideal is an army which asks sharp questions about the justification of the war, before they fight it. |
| 23604 | Volunteer soldiers accept the risk of attack, but they don't agree to it, or to their deaths [McMahan] |
| Full Idea: When soldiers go to war, they undoubtedly assume a certain risk. They voluntarily expose themselves to a significant risk of being attacked. But this is entirely different from consenting to being attacked. | |
| From: Jeff McMahan (Killing in War [2009], 2.2.1) | |
| A reaction: This is his response to Walzer's thought that soldiers resemble people who volunteer for a boxing match. The sailors at Pearl Harbour obviously didn't consent to the attack, or accept the Japanese right to kill them. |
| 23608 | If being part of a big collective relieves soldiers of moral responsibility, why not the leaders too? [McMahan] |
| Full Idea: If acting as an agent of a political collective justifies the combatants fighting an unjust war, that should also release the leaders from responsibility for their role in the fighting of that war. No one ever explains why this is not so. | |
| From: Jeff McMahan (Killing in War [2009], 2.5) | |
| A reaction: At the very least there seems to be a problem of the cut off point between innocent soldiers and culpable leaders. Which rank in the army or executive triggers the blame? |
| 23610 | If soldiers can't refuse to fight in unjust wars, can they choose to fight in just wars? [McMahan] |
| Full Idea: There is a certain symmetry here. The permissibility of disobeying a command to fight in an unjust war suggests the permissibility of disobeying a command not to fight in a just war. | |
| From: Jeff McMahan (Killing in War [2009], 2.7) | |
| A reaction: The argument considered here is that since we could never allow soldiers to choose to fight in their own wars, we similarly cannot let them opt out of the official wars. Implying obedience is absolute. Soldiers don't get to 'choose' anything! |
| 23613 | Equality is both sides have permission, or both sides are justified, or one justified the other permitted [McMahan] |
| Full Idea: Moral equality means either 1) because just combatants are permitted to fight in a just way, so are the unjust , or 2) because the just are justified, so are the unjust, or 3) because the just are justified, the unjust are therefore permitted. | |
| From: Jeff McMahan (Killing in War [2009], 3.1.2) | |
| A reaction: [summary] McMahan calls 1) the weak version, and 2) the strong. He suggests that although 3) is unusual, it is what most people believe - that if the good are justified, the bad are permitted to fight back. He rejects them all. |
| 23615 | Fighting unjustly under duress does not justify it, or permit it, but it may excuse it [McMahan] |
| Full Idea: It is said that combatants are compelled to fight; they have no choice. But duress is not a justification; nor does it ground a permission - not even a subjective permission. It is, instead, an excusing condition. | |
| From: Jeff McMahan (Killing in War [2009], 3.1.2) | |
| A reaction: The 'subjective' permission is believing you are just, even if you aren't. A nice, accurate and true distinction made by McMahan, I think. It is roughly our postwar attitude to the Nazi army. |
| 23605 | Soldiers cannot know enough facts to evaluate the justice of their war [McMahan] |
| Full Idea: When soldiers are commanded to fight, they cannot reasonably be expected to have the factual knowledge necessary to evaluate the war as just or unjust. | |
| From: Jeff McMahan (Killing in War [2009], 2.3) | |
| A reaction: This is part of the 'epistemic' justification for a soldier to fight in an unjust war. Sometimes soldiers do have enoough knowledge, especially if they join up late on in a war, when they have studied and observed its progress. |
| 23602 | Innocence implies not being morally responsible, rather than merely being guiltless [McMahan] |
| Full Idea: My alternative conception is that one is 'innocent' if one is neither morally responsible for nor guilty of a wrong. Classical theory focused on guilt, but I think we should focus on moral responsibility (which is something less). | |
| From: Jeff McMahan (Killing in War [2009], 1.4) | |
| A reaction: This seems to make the supporters of evil equally liable to attack with its perpetrators. But you can observe perpetration a lot more easily than you can observe support. |
| 23618 | Unconditional surrender can't be demanded, since evil losers still have legitimate conditions [McMahan] |
| Full Idea: Achieving unconditional surrender can never be a justification for the continuation of war, since there are always conditions that a vanquished adversary, no matter how evil, can be justified in demanding. | |
| From: Jeff McMahan (Killing in War [2009], 3.3.1) | |
| A reaction: McMahan is particularly discussing Hiroshima, but this also applies to the European war in 1945. Presumably a civilised victor will grant the conditions which the losers would have demanded, and that probably happened in 1945. It's about power. |
| 13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
| Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
| From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
| A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
| 2102 | Atomism is irrational because it suggests that two atoms can be indistinguishable [Leibniz] |
| Full Idea: There are no two individuals indiscernible from one another - leaves, or drops of water, for example. This is an argument against atoms, which, like the void, are opposed to the principles of a true metaphysic. | |
| From: Gottfried Leibniz (Letters to Samuel Clarke [1716], 4.04) |
| 2105 | Things are infinitely subdivisible and contain new worlds, which atoms would make impossible [Leibniz] |
| Full Idea: The least corpuscle is actually subdivided ad infinitum and contains a world of new created things, which this universe would lack if this corpuscle were an atom. | |
| From: Gottfried Leibniz (Letters to Samuel Clarke [1716], 4.PS) |
| 2106 | The only simple things are monads, with no parts or extension [Leibniz] |
| Full Idea: According to me there is nothing simple except true monads, which have no parts and no extensions. | |
| From: Gottfried Leibniz (Letters to Samuel Clarke [1716], 5.24) |
| 20965 | Leibniz upheld conservations of momentum and energy [Leibniz, by Papineau] |
| Full Idea: In place of Descartes's conservation of 'quantity of motion', Leibniz upheld both the conservation of linear momentum and the conservation of kinetic energy. | |
| From: report of Gottfried Leibniz (Letters to Samuel Clarke [1716], 5th paper) by David Papineau - Thinking about Consciousness App 2 | |
| A reaction: The point is that momentum involves velocity (which includes direction) rather than speed. Leibniz more or less invented the concept of 'energy' ('vis viva'). Papineau says these two leave no room for causation by mental substance. |
| 2103 | The idea that the universe could be moved forward with no other change is just a fantasy [Leibniz] |
| Full Idea: To say that God could cause the universe to move forward in a straight line or otherwise without changing it in any other way is another fanciful supposition. | |
| From: Gottfried Leibniz (Letters to Samuel Clarke [1716], 4.14) |
| 2100 | Space and time are purely relative [Leibniz] |
| Full Idea: I have more than once stated that I held space to be something purely relative, like time. | |
| From: Gottfried Leibniz (Letters to Samuel Clarke [1716], 3.4) |
| 20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
| Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
| From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
| A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |
| 2107 | No time exists except instants, and instants are not even a part of time, so time does not exist [Leibniz] |
| Full Idea: How could a thing exist, no part of which ever exists? In the case of time, nothing exists but instants, and an instant is not even a part of time. | |
| From: Gottfried Leibniz (Letters to Samuel Clarke [1716], 5.49) |
| 2101 | If everything in the universe happened a year earlier, there would be no discernible difference [Leibniz] |
| Full Idea: To ask why God did not make everything a year sooner would be reasonable if time were something apart from temporal things, but time is just the succession of things, which remains the same if the universe is created a year sooner. | |
| From: Gottfried Leibniz (Letters to Samuel Clarke [1716], 3.6) |
| 22894 | If time were absolute that would make God's existence dependent on it [Leibniz, by Bardon] |
| Full Idea: Leibniz argues that if time is a thing in itself, and God is 'in' time, then God would be dependent for His existence on the existence of time. | |
| From: report of Gottfried Leibniz (Letters to Samuel Clarke [1716]) by Adrian Bardon - Brief History of the Philosophy of Time 3 'Newton' | |
| A reaction: Hence Leibniz says time is merely relations between events. Not sure what he thinks an event is. What is God made of? Is there some divine matter upon which God's existence must depend? |
| 2099 | The existence of God, and all metaphysics, follows from the Principle of Sufficient Reason [Leibniz] |
| Full Idea: By this principle alone, that there must be a sufficient reason why things are thus rather than otherwise, I prove the existence of the Divinity, and all the rest of metaphysics or natural theology. | |
| From: Gottfried Leibniz (Letters to Samuel Clarke [1716], §2) |