43 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. |
| 5311 | If observation goes up a level, we expect the laws of the lower level to remain in force [Wilson,EO] |
| Full Idea: When the observer shifts his attention from one level of organisation to the next, as from physics to chemistry, he expects to find obedience to all the laws of the levels below. | |
| From: Edmund O. Wilson (On Human Nature [1978], Ch.1) | |
| A reaction: This seems to state a necessary condition of reduction, but not a sufficient one. Wilson points out that new phenomena emerge at higher levels. This principle is similar to Hume's argument against miracles. You don't easily overthrow basic laws. |
| 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). |
| 5312 | A child first sees objects as distinct, and later as members of groups [Wilson,EO] |
| Full Idea: From a single-minded effort to move objects a child's activity grows into a detached reflection on the movements themselves. The objects are first perceived as distinct entities, and then as members of groups to be classified. | |
| From: Edmund O. Wilson (On Human Nature [1978], Ch.3) | |
| A reaction: This does not, of course, prove anything about the philosophical problems of universals, but it does seem to pinpoint the stage in human development when 'universals' are perceived. The basis seems to be groups or sets, but how do we spot those? |
| 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. |
| 5309 | Beliefs are really enabling mechanisms for survival [Wilson,EO] |
| Full Idea: Beliefs are really enabling mechanisms for survival. | |
| From: Edmund O. Wilson (On Human Nature [1978], Ch.1) | |
| A reaction: How does he know this proposition which he asserts so confidently? Obvious counterexamples seem to be utterly trivial beliefs, and self-destructive beliefs. What is the evolutionary value of low self-esteem? Still, you see his point. |
| 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. |
| 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] |
| 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. |
| 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) |
| 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) |
| 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) |
| 5310 | Philosophers study the consequences of ethics instead of its origins [Wilson,EO] |
| Full Idea: Philosophers examine the precepts of ethical systems with reference to their consequences and not their origins. | |
| From: Edmund O. Wilson (On Human Nature [1978], Ch.1) | |
| A reaction: He is interested in biological origins, but it strikes me that every moral theory has some account of the origins of morality, be it pure reason, or the love of pleasure, or human nature, or eternal ideas, or the will of God, or selfish desires. |
| 22187 | Genetic behaviours that have enhanced human success include aggression, rape and xenophobia [Wilson,EO, by Okasha] |
| Full Idea: Wilson claimed that many human behaviours, including aggression, rape, and xenophobia, had a genetic basis, and were adaptations favoured by natural selection because they enhanced the reproductive success of our ancestors. | |
| From: report of Edmund O. Wilson (Sociobiology [1975]) by Samir Okasha - Philosophy of Science: Very Short Intro (2nd ed) 7 | |
| A reaction: This led to the Sociobiology Wars, when E.O. Wilson was attacked by Richard Lewontin and Stephen Jay Gould. |
| 5313 | The rules of human decision-making converge and overlap in a 'human nature' [Wilson,EO] |
| Full Idea: The rules followed in human decision-making are tight enough to produce a broad overlap in the decisions taken by all individuals, and hence a convergence powerful enough to be labelled 'human nature'. | |
| From: Edmund O. Wilson (On Human Nature [1978], Ch.3) | |
| A reaction: This is a nice empirical criterion for asserting the existence of human nature, and it seems right to examine decisions, rather than more thoughtless or conformist behaviour. Existentialists dream of new possibilities, but the old ways always seem best… |
| 5316 | We undermine altruism by rewarding it, but we reward it to encourage it [Wilson,EO] |
| Full Idea: By sanctifying altruism in order to reward it we make it less true, but by that means we promote its recurrence in others. | |
| From: Edmund O. Wilson (On Human Nature [1978], Ch.7) | |
| A reaction: So is my preference for not rewarding (or even noticing) altruism an anti-social tendency. The very conspicuous charity of sponsorship seems somehow inferior to the truly anonymous gift. Or super-altruism is very public, to encourage it in others? |
| 5318 | Pure hard-core altruism based on kin selection is the enemy of civilisation [Wilson,EO] |
| Full Idea: Pure hard-core altruism based on kin selection is the enemy of civilisation. | |
| From: Edmund O. Wilson (On Human Nature [1978], Ch.7) | |
| A reaction: By 'hard-core' he means suicidally self-sacrificing, rather than extensive. This seems a good thesis. It strikes me that the development of civil society is often impeded by family loyalty, such as in the case of the Mafia. |
| 5317 | The actor is most convincing who believes that his performance is real [Wilson,EO] |
| Full Idea: The actor is most convincing who believes that his performance is real. | |
| From: Edmund O. Wilson (On Human Nature [1978], Ch.7) | |
| A reaction: This is a key element of social contract theory. It shows why natural selection of truly altruistic traits might be beneficial to individuals, provided they are surrounded by possible recipricators. We trust those who are genuine and sincere. |
| 20662 | The biology of societies: kin selection, parenting, mating; status, territory, contracts [Wilson,EO] |
| Full Idea: Societies are ordered around six sociobiological principles: kin selection; parental investment; mating strategy; status; territorial expansion and defence; contractual agreement. | |
| From: Edmund O. Wilson (Consilience [1998], 19 'Intro'), quoted by Peter Watson - Convergence | |
| A reaction: I'm not sure I trust such a precise list. Personally I'm in society because I'm too frightend to drop out. So where is 'defence'? Still, I like attempts at assembling such a list. Politics needs grounding. |
| 5308 | The only human purpose is that created by our genetic history [Wilson,EO] |
| Full Idea: No species, ours included, possesses a purpose beyond the imperatives created by its genetic history. | |
| From: Edmund O. Wilson (On Human Nature [1978], Ch.1) | |
| A reaction: This invites the question of what that purpose is perceived to be. Some people feel an imperative to play the piano all day, so presumably genetic history has created that feeling. Presumably we can also choose a purpose, even extinction. |
| 5314 | Cultural evolution is Lamarckian and fast, biological evolution is Darwinian and slow [Wilson,EO] |
| Full Idea: Cultural evolution is Lamarckian and very fast, whereas biological evolution is Darwinian and usually very slow. | |
| From: Edmund O. Wilson (On Human Nature [1978], Ch.4) | |
| A reaction: An intriguing point, given how discredited Lamarckian evolution is. It links with the Dawkins idea of 'memes' - cultural ideas which spread very fast. Is biological evolution suddenly about to become Lamarckian, as culture influences biology? |
| 5315 | Over 99 percent of human evolution has been in the hunter-gatherer phase [Wilson,EO] |
| Full Idea: Selection pressures of hunter-gatherer existence have persisted for over 99 percent of human genetic evolution. | |
| From: Edmund O. Wilson (On Human Nature [1978], Ch.4) | |
| A reaction: This seems a key point to bear in mind when assessing human nature. Hunter-gathering isn't just one tendency in our genetics; it more or less constitutes everything we are. |
| 5320 | It is estimated that mankind has produced 100,000 religions [Wilson,EO] |
| Full Idea: Since the first recorded religion (in Iraq 60,000 years ago) it is estimated that mankind has produced in the order of one hundred thousand religions. | |
| From: Edmund O. Wilson (On Human Nature [1978], Ch.8) | |
| A reaction: If asked to guess the number, I would probably have said '200'! This staggering figure seems to argue both ways - it suggest a certain arbitrariness in the details of religions, but an extremely intense drive to have some sort of religious belief. |
| 1513 | The Egyptians were the first to say the soul is immortal and reincarnated [Herodotus] |
| Full Idea: The Egyptians were the first to claim that the soul of a human being is immortal, and that each time the body dies the soul enters another creature just as it is being born. | |
| From: Herodotus (The Histories [c.435 BCE], 2.123.2) |