40 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) |
| 7439 | The qualities involved in sensations are entirely intentional [Anscombe, by Armstrong] |
| Full Idea: Anscombe argued that the qualities involved in sensations are one and all intentional only (and I think this holds even for the bodily sensations). | |
| From: report of G.E.M. Anscombe (The Intentionality of Sensation [1965]) by David M. Armstrong - Pref to new 'Materialist Theory' p.xxii | |
| A reaction: Compare Harry Gildersleve's exactly opposite proposal in Idea 7272. I think I am coming round to the Anscombe view, which builds the more mysterious up from the less mysterious. Gildersleve must explain how atomic qualia arise. |
| 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. |
| 8353 | Freedom involves acting according to an idea [Anscombe] |
| Full Idea: Freedom at least involves the power of acting according to an idea. | |
| From: G.E.M. Anscombe (Causality and Determinism [1971], §2) | |
| A reaction: Since 'you' presumably have to sit above the idea and pass a judgement on it, then the same principle should apply to acting on a desire, which presumably 'you' could reject because it just wasn't attractive enough. |
| 8352 | To believe in determinism, one must believe in a system which determines events [Anscombe] |
| Full Idea: 'The ball's path is determined' must mean 'there is only one possible path for the ball (assuming no air currents)', but what ground could one have for believing this, if one does not believe in some system for which it is a consequence? | |
| From: G.E.M. Anscombe (Causality and Determinism [1971], §2) | |
| A reaction: This seems right, but it doesn't follow that one has to know the full details of the system. The system might just be the best explanation, or even a matter of vague faith. It might, though, be just that you can't imagine any other outcome. |
| 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) |
| 20041 | Intentional actions are those which are explained by giving the reason for so acting [Anscombe] |
| Full Idea: Intentional actions are those to which a certain sense of the question 'Why?' is given application; the sense is of course that in which the answer, if positive, gives a reason for acting. | |
| From: G.E.M. Anscombe (Intention [1957], p.9), quoted by Rowland Stout - Action 2 'Two kinds' | |
| A reaction: This works better for grand large-scale actions than for small ones, like taking the knife out of the drawer before the fork. Kahnemann nowadays tells us that the reasons we articulate might not be the ones that are operative. |
| 8070 | It would be better to point to failings of character, than to moral wrongness of actions [Anscombe] |
| Full Idea: It would be a great improvement if, instead of 'morally wrong', one always named a genus such as 'untruthful', 'unchaste', or 'unjust'. | |
| From: G.E.M. Anscombe (Modern Moral Philosophy [1958], p.183) | |
| A reaction: People are indeed much more struck by the suggestion that they have a weakness of character, rather than that they have just done something wrong. This is Anscombe's first great appeal for a return to virtue as the basis of ethics. |
| 8065 | 'Ought' and 'right' are survivals from earlier ethics, and should be jettisoned [Anscombe] |
| Full Idea: The moral sense of 'ought' and of what is right should be jettisoned, if possible, because they are survivals from an earlier conception of ethics, and are only harmful without it. | |
| From: G.E.M. Anscombe (Modern Moral Philosophy [1958], p.175) | |
| A reaction: This is part of a revolutionary proposal to return to virtue theory, and has had a great influence (e.g. on me). Richard Taylor gives a good account of how duty lost its social and religious underpinnings. Our duties now seem to be purely contractual. |
| 8069 | Between Aristotle and us, a Judaeo-Christian legal conception of ethics was developed [Anscombe] |
| Full Idea: Between Aristotle and us came Christianity, with its law conception of ethics, and Christianity derived its ethical notions from the Torah. | |
| From: G.E.M. Anscombe (Modern Moral Philosophy [1958], p.179) | |
| A reaction: While I am a fan of the primacy of the virtues in ethical thinking, I am doubtful about the complete elimination of laws (e.g. by Particularists). The law teaches us the virtues, and reminds us of them (like speed-limit signs). |
| 7810 | The 'Eumenides' of Aeschylus shows blood feuds replaced by law [Aeschylus, by Grayling] |
| Full Idea: The 'Eumenides' of Aeschylus tells how the old rule of revenge and blood feud was replaced by a due process of law before a civil jury. | |
| From: report of Aeschylus (The Eumenides [c.458 BCE]) by A.C. Grayling - What is Good? Ch.2 | |
| A reaction: Compare Idea 1659, where this revolution is attributed to Protagoras (a little later than Aeschylus). I take the rule of law and of society to be above all the rule of reason, because the aim is calm objectivity instead of emotion. |
| 8351 | With diseases we easily trace a cause from an effect, but we cannot predict effects [Anscombe] |
| Full Idea: It is much easier to trace effects back to causes with certainty than to predict effects from causes. If I have one contact with someone with a disease and I get it, we suppose I got it from him, but a doctor cannot predict a disease from one contact. | |
| From: G.E.M. Anscombe (Causality and Determinism [1971], §1) | |
| A reaction: An interesting, and obviously correct, observation. Her point is that we get more certainty of causes from observing a singular effect than we get certainty of effects from regularities or laws. |
| 4777 | The word 'cause' is an abstraction from a group of causal terms in a language (scrape, push..) [Anscombe] |
| Full Idea: The word "cause" can be added to a language in which are already represented many causal concepts; a small selection: scrape, push, wet, carry, eat, burn, knock over, keep off, squash, make, hurt. | |
| From: G.E.M. Anscombe (Causality and Determinism [1971], p.93) | |
| A reaction: An interesting point, perhaps reinforcing the Humean idea of causation as a 'natural belief', or the Kantian view of it as a category of thought. Or maybe causation is built into language because it is a feature of reality… |
| 10363 | Causation is relative to how we describe the primary relata [Anscombe, by Schaffer,J] |
| Full Idea: Anscombe has inspired the view that causation is an intensional relation, and takes it to be relative to the descriptions of the primary relata. | |
| From: report of G.E.M. Anscombe (Causality and Determinism [1971], 1) by Jonathan Schaffer - The Metaphysics of Causation 1 | |
| A reaction: It seems too linguistic to say that there is nothing more to it. It seems relevant in human examples, but if a landslide crushes a tree, what difference does the description make? 'It was just a few rocks and some miserable little tree'. No excuse! |
| 8350 | Since Mill causation has usually been explained by necessary and sufficient conditions [Anscombe] |
| Full Idea: Since Mill it has been fairly common to explain causation one way or another in terms of 'necessary' and 'sufficient' conditions. | |
| From: G.E.M. Anscombe (Causality and Determinism [1971], §1) | |
| A reaction: Interesting to see what Hume implies about these criteria. Anscombe is going to propose that causal events are fairly self-evident and self-explanatory, and don't need analyses of conditions. Another approach is regularities and laws. |