52 ideas
| 11051 | Frege's logical approach dominates the analytical tradition [Hanna] |
| Full Idea: Pure logic constantly controls Frege's philosophy, and in turn Frege's logically oriented philosophy constantly controls the analytic tradition. | |
| From: Robert Hanna (Rationality and Logic [2006], 1.1) | |
| A reaction: Hanna seeks to reintroduce the dreaded psychological aspect of logic, and I say 'good for him'. |
| 11054 | Scientism says most knowledge comes from the exact sciences [Hanna] |
| Full Idea: Scientism says that the exact sciences are the leading sources of knowledge about the world. | |
| From: Robert Hanna (Rationality and Logic [2006], 1.2) | |
| A reaction: I almost agree, but I would describe the exact sciences as the chief 'evidence' for our knowledge, with the chief 'source' being our own ability to make coherent sense of the evidence. Exact sciences rest on mathematics. |
| 11070 | 'Denying the antecedent' fallacy: φ→ψ, ¬φ, so ¬ψ [Hanna] |
| Full Idea: The fallacy of 'denying the antecedent' is of the form φ→ψ, ¬φ, so ¬ψ. | |
| From: Robert Hanna (Rationality and Logic [2006], 5.4) |
| 11071 | 'Affirming the consequent' fallacy: φ→ψ, ψ, so φ [Hanna] |
| Full Idea: The fallacy of 'affirming the consequent' is of the form φ→ψ, ψ, so φ. | |
| From: Robert Hanna (Rationality and Logic [2006], 5.4) |
| 11088 | We can list at least fourteen informal fallacies [Hanna] |
| Full Idea: Informal fallacies: appeals to force, circumstantial factors, ignorance, pity, popular consensus, authority, generalisation, confused causes, begging the question, complex questions, irrelevance, equivocation, black-and-white, slippery slope etc. | |
| From: Robert Hanna (Rationality and Logic [2006], 7.3) |
| 11059 | Circular arguments are formally valid, though informally inadmissible [Hanna] |
| Full Idea: A circular argument - one whose conclusion is to be found among its premises - is inadmissible in most informal contexts, even though it is formally valid. | |
| From: Robert Hanna (Rationality and Logic [2006], 2.1) | |
| A reaction: Presumably this is a matter of conversational implicature - that you are under a conventional obligation to say things which go somewhere, rather than circling around their starting place. |
| 11089 | Formally, composition and division fallacies occur in mereology [Hanna] |
| Full Idea: Informal fallacies of composition and division go over into formal fallacies of mereological logic. | |
| From: Robert Hanna (Rationality and Logic [2006], 7.3) |
| 11058 | Logic is explanatorily and ontologically dependent on rational animals [Hanna] |
| Full Idea: Logic is explanatorily and ontologically dependent on rational animals. | |
| From: Robert Hanna (Rationality and Logic [2006], 1.6) | |
| A reaction: This is a splendid defiance of the standard Fregean view of logic as having an inner validity of its own, having nothing to do with the psychology of thinkers. But if Hanna is right, why does logical consequence seem to be necessary? |
| 11072 | Logic is personal and variable, but it has a universal core [Hanna] |
| Full Idea: Beyond an innate and thus universally share protologic, each reasoner's mental logic is only more or less similar to the mental logic of any other reasoner. | |
| From: Robert Hanna (Rationality and Logic [2006], 5.7) | |
| A reaction: This is the main thesis of Hanna's book. I like the combination of this idea with Stephen Read's remark that each student should work out a personal logic which has their own private endorsement. |
| 11061 | Intensional consequence is based on the content of the concepts [Hanna] |
| Full Idea: In intensional logic the consequence relation is based on the form or content of the concepts or properties expressed by the predicates. | |
| From: Robert Hanna (Rationality and Logic [2006], 2.2) |
| 11063 | Logicism struggles because there is no decent theory of analyticity [Hanna] |
| Full Idea: All versions of the thesis that arithmetic is reducible to logic remain questionable as long as no good theory of analyticity is available. | |
| From: Robert Hanna (Rationality and Logic [2006], 2.4) | |
| A reaction: He rejects the attempts by Frege, Wittgenstein and Carnap to provide a theory of analyticity. |
| 11055 | Supervenience can add covariation, upward dependence, and nomological connection [Hanna] |
| Full Idea: 'Strong supervenience' involves necessary covariation of the properties, and upward dependence of higher level on lower level. ...If we add a nomological connection between the two, then we have 'superdupervenience'. | |
| From: Robert Hanna (Rationality and Logic [2006], 1.2) | |
| A reaction: [compressed] Very helpful. A superdupervenient relationship between mind and brain would be rather baffling if they were not essentially the same thing. (which is what I take them to be). |
| 11083 | A sentence is necessary if it is true in a set of worlds, and nonfalse in the other worlds [Hanna] |
| Full Idea: On my view, necessity is the truth of a sentence in every member of a set of possible worlds, together with its nonfalsity in every other possible worlds. | |
| From: Robert Hanna (Rationality and Logic [2006], 6.6) |
| 11086 | Metaphysical necessity can be 'weak' (same as logical) and 'strong' (based on essences) [Hanna] |
| Full Idea: Weak metaphysical necessity is either over the set of all logically possible worlds (in which case it is the same as logical necessity), or it is of a smaller set of worlds, and is determined by the underlying essence or nature of the actual world. | |
| From: Robert Hanna (Rationality and Logic [2006], 6.6) | |
| A reaction: I take the first to be of no interest, as I have no interest in a world which is somehow rated as logically possible, but is not naturally possible. The second type should the principle aim of all human cognitive enquiry. The strong version is synthetic. |
| 11084 | Logical necessity is truth in all logically possible worlds, because of laws and concepts [Hanna] |
| Full Idea: Logical necessity is the truth of a sentence by virtue of logical laws or intrinsic conceptual connections alone, and thus true in all logically possible worlds. Put in traditional terms, logical necessity is analyticity. | |
| From: Robert Hanna (Rationality and Logic [2006], 6.6) |
| 11085 | Nomological necessity is truth in all logically possible worlds with our laws [Hanna] |
| Full Idea: Physical or nomological necessity is the truth of a sentence in all logically possible worlds governed by our actual laws of nature. | |
| From: Robert Hanna (Rationality and Logic [2006], 6.6) | |
| A reaction: Personally I think 'natural necessity' is the best label for this, as it avoids firm commitment to reductive physicalism, and it also avoids commitment to actual necessitating laws. |
| 11077 | Intuition includes apriority, clarity, modality, authority, fallibility and no inferences [Hanna] |
| Full Idea: The nine features of intuition are: a mental act, apriority, content-comprehensiveness, clarity and distinctness, strict-modality-attributivity, authoritativeness,noninferentiality, cognitive indispensability, and fallibility. | |
| From: Robert Hanna (Rationality and Logic [2006], 6.4) | |
| A reaction: [See Hanna for a full explanation of this lot] Seems like a good stab at it. Note the trade-off between authority and fallibility. |
| 11080 | Intuition is more like memory, imagination or understanding, than like perception [Hanna] |
| Full Idea: There is no reason why intuition should be cognitively analogous not to sense perception but instead to either memory, imagination, or conceptual understanding. | |
| From: Robert Hanna (Rationality and Logic [2006], 6.5) | |
| A reaction: It is Russell's spotting the analogy with memory that made me come to believe that a priori knowledge is possible, as long as we accept it as being fallible. [Hanna has a good discussion of intuition; he votes for the imagination analogy] |
| 11078 | Intuition is only outside the 'space of reasons' if all reasons are inferential [Hanna] |
| Full Idea: Intuition is outside the 'space of reasons' if we assume that all reasons are inferential, but inside if we assume that reasons need not always be inferential. | |
| From: Robert Hanna (Rationality and Logic [2006], 6.4) | |
| A reaction: I take it that intuition can be firmly inside the space of reasons, and that not all reasons are inferential. |
| 11053 | Explanatory reduction is stronger than ontological reduction [Hanna] |
| Full Idea: As standardly construed, reduction can be either explanatory or ontological. Explanatory reduction is the strongest sort of reduction. ...Ontological reduction can still have an 'explanatory gap'. | |
| From: Robert Hanna (Rationality and Logic [2006], 1.1) |
| 11081 | Imagination grasps abstracta, generates images, and has its own correctness conditions [Hanna] |
| Full Idea: Three features of imagination are that its objects can be abstract, that it generates spatial images directly available to introspection, and its correctness conditions are not based on either efficacious causation or effective tracking. | |
| From: Robert Hanna (Rationality and Logic [2006], 6.6) | |
| A reaction: Hanna makes the imagination faculty central to our grasp of his proto-logic. |
| 11082 | Should we take the 'depictivist' or the 'descriptivist/propositionalist' view of mental imagery? [Hanna] |
| Full Idea: In the debate in cognitive science on the nature of mental imagery, there is a 'depictivist' side (Johnson-Laird, Kosslyn, Shepard - good images are isomorphic), and a 'descriptivist' or 'propositionalist' side (Pylyshyn and others). | |
| From: Robert Hanna (Rationality and Logic [2006], 6.6) | |
| A reaction: Hanna votes firmly in favour of the first view, and implies that they have more or less won the debate. |
| 11067 | Rational animals have a normative concept of necessity [Hanna] |
| Full Idea: A rational animal is one that is a normative-reflective possessor of the concepts of necessity, certainty and unconditional obligation. | |
| From: Robert Hanna (Rationality and Logic [2006], 4.0) | |
| A reaction: The addition of obligation shows the Kantian roots of this. It isn't enough just to possess a few concepts. You wouldn't count as rational if you didn't desire truth, as well as understanding it. Robots be warned. |
| 11068 | One tradition says talking is the essence of rationality; the other says the essence is logic [Hanna] |
| Full Idea: In the tradition of Descartes, Chomsky and Davidson, rational animals are essentially talking animals. But in the view of Kant, and perhaps Fodor, it is the cognitive capacity for logic that is the essence of human rationality. | |
| From: Robert Hanna (Rationality and Logic [2006], 4.9) |
| 11047 | Hegelian holistic rationality is the capacity to seek coherence [Hanna] |
| Full Idea: The 'holistic' (Hegelian) sense of rationality means the capacity for systematically seeking coherence (or 'reflective equilibrium') across a network or web of beliefs, desires, emotions, intentions and volitions. Traditionally 'the truth is the whole'. | |
| From: Robert Hanna (Rationality and Logic [2006], Intro) | |
| A reaction: On the whole this is my preferred view (which sounds Quinean as well as Hegelian), though I reject the notion that truth is a whole. I take coherence to be the hallmark of justification, though not of truth, and reason aims to justify. |
| 11048 | Humean Instrumental rationality is the capacity to seek contingent truths [Hanna] |
| Full Idea: The 'instrumental' (Humean) sense of rationality means a capacity for generating or recognizing contingent truths, contextually normative rules, consequentialist obligations, and hypothetical 'ought' claims. Reason is 'the slave of the passions'. | |
| From: Robert Hanna (Rationality and Logic [2006], Intro) |
| 11046 | Kantian principled rationality is recognition of a priori universal truths [Hanna] |
| Full Idea: The 'principled' (Kantian) sense of rationality means the possession of a capacity for generating or recognizing necessary truths, a priori beliefs, strictly universal normative rules, nonconsequentialist moral obligations, and categorical 'ought' claims. | |
| From: Robert Hanna (Rationality and Logic [2006], Intro) |
| 11045 | Most psychologists are now cognitivists [Hanna] |
| Full Idea: Most psychologists have now dropped behaviourism and adopted cognitivism: the thesis that the rational human mind is essentially an active innately specified information-processor. | |
| From: Robert Hanna (Rationality and Logic [2006], Intro) |
| 19216 | Propositions (such as 'that dog is barking') only exist if their items exist [Williamson] |
| Full Idea: A proposition about an item exists only if that item exists... how could something be the proposition that that dog is barking in circumstances in which that dog does not exist? | |
| From: Timothy Williamson (Necessary Existents [2002], p.240), quoted by Trenton Merricks - Propositions | |
| A reaction: This is a view of propositions I can't make sense of. If I'm under an illusion that there is a dog barking nearby, when there isn't one, can I not say 'that dog is barking'? If I haven't expressed a proposition, what have I done? |
| 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. |
| 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. |
| 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. |
| 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. |