44 ideas
| 8093 | Seek wisdom rather than truth; it is easier [Joubert] |
| Full Idea: To seek wisdom rather than truth. It is more within our grasp. | |
| From: Joseph Joubert (Notebooks [1800], 1797) | |
| A reaction: A nice challenge to the traditional goal of philosophy. The idea that we should 'seek truth' only seems to have emerged during the Reformation. The Greeks may well never have dreamed of such a thing. |
| 8095 | We must think with our entire body and soul [Joubert] |
| Full Idea: Everything we think must be thought with our entire being, body and soul. | |
| From: Joseph Joubert (Notebooks [1800], 1798) | |
| A reaction: Not just that thinking must be a whole-hearted activity, but that the very contents of our thinking will be better if it arises out of being a physical creature, and not just a disembodied reasoner. Maybe the bowels are not needed to analyse set theory. |
| 8107 | The love of certainty holds us back in metaphysics [Joubert] |
| Full Idea: What stops or holds us back in metaphysics is a love of certainty. | |
| From: Joseph Joubert (Notebooks [1800], 1814) | |
| A reaction: This is a prominent truth from the age of Descartes, but may have diminished in the twenty-first century. The very best metaphysicians (e.g. Aristotle and Lewis) always end in a trail of dots when things become unsure. |
| 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. |
| 8099 | The truths of reason instruct, but they do not illuminate [Joubert] |
| Full Idea: There are truths that instruct, perhaps, but they do not illuminate. In this class are all the truths of reasoning. | |
| From: Joseph Joubert (Notebooks [1800], 1800) | |
| A reaction: A rather romantic view, which strikes me as false. An inspiring truth can suddenly collapse when you see why it must be false. Equally a line of reasoning can lead to a truth which need becomes an illumination. |
| 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) |
| 8098 | Truth consists of having the same idea about something that God has [Joubert] |
| Full Idea: Truth consists of having the same idea about something that God has. | |
| From: Joseph Joubert (Notebooks [1800], 1800) | |
| A reaction: Presumably sceptics about the existence of objective truth must also be sceptical about the possibility of such a God. I think Joubert is close to the nature of truth here. It is a remote and barely imaginable ideal. |
| 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. |
| 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] |
| 8101 | To know is to see inside oneself [Joubert] |
| Full Idea: To know: it is to see inside oneself. | |
| From: Joseph Joubert (Notebooks [1800], 1800) | |
| A reaction: Extreme internalism about justification! Personally I am becoming convinced that 'know' (unlike 'believe' and 'true') is an entirely social concept. Fools spend a lot of time instrospecting; wise people ask around, and check in books. |
| 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) |
| 16861 | A false theory could hardly rival the explanatory power of natural selection [Darwin] |
| Full Idea: It can hardly be supposed that a false theory would explain, in so satisfactory a manner as does the theory of natural selection, the several large classes of facts above specified. | |
| From: Charles Darwin (The Origin of the Species [1859], p.476), quoted by Peter Lipton - Inference to the Best Explanation (2nd) 11 'The scientific' | |
| A reaction: More needs to be said, since the whims of God could explain absolutely everything (in a manner that would be somehow less that fully satisfying to the enquiring intellect). |
| 8094 | The imagination has made more discoveries than the eye [Joubert] |
| Full Idea: The imagination has made more discoveries than the eye. | |
| From: Joseph Joubert (Notebooks [1800], 1797) | |
| A reaction: As a fan of the imagination, I love this one. I suspect that imagination, which was marginalised by Descartes, is actually the single most important aspect of thought (in slugs as well as humans). Abstraction requires imagination. |
| 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. |
| 8103 | A thought is as real as a cannon ball [Joubert] |
| Full Idea: A thought is a thing as real as a cannon ball. | |
| From: Joseph Joubert (Notebooks [1800], 1801) | |
| A reaction: Nice. The realisation of a thought can strike someone as if they have been assaulted, and hearing some remarks can be as bad as being stabbed. That is quite apart from political consequences. Joubert is good on the physicality of thinking. |
| 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) |
| 8100 | Where does the bird's idea of a nest come from? [Joubert] |
| Full Idea: The idea of the nest in the bird's mind, where does it come from? | |
| From: Joseph Joubert (Notebooks [1800], 1800) | |
| A reaction: I think this is a very striking example in support of innate ideas. Most animal behaviour can be explained as responses to stimuli, but the bird seems to hold a model in its mind while it collects its materials. |
| 8096 | He gives his body up to pleasure, but not his soul [Joubert] |
| Full Idea: He gives his body up to pleasure, but not his soul. | |
| From: Joseph Joubert (Notebooks [1800], 1799) | |
| A reaction: A rather crucial distinction in the world of hedonism. There seems something sincere about someone who pursues pleasure body and soul, and something fractured about the pursuit of pleasure without real commitment. The split seems possible. |
| 8104 | What will you think of pleasures when you no longer enjoy them? [Joubert] |
| Full Idea: What will you think of pleasures when you no longer enjoy them? | |
| From: Joseph Joubert (Notebooks [1800], 1802) | |
| A reaction: A lovely test question for aspiring young hedonists! It doesn't follow at all that we will despise past pleasures. The judgement may be utilitarian - that we regret the pleasures that harmed others, but love the harmless ones. Shame is social. |
| 8097 | Virtue is hard if we are scorned; we need support [Joubert] |
| Full Idea: It would be difficult to be scorned and to live virtuously. We have need of support. | |
| From: Joseph Joubert (Notebooks [1800], 1800) | |
| A reaction: He seems to have hit on what I take to be one of the keys to Aristotle: that virtue is a social matter, requiring both upbringing and a healthy culture. But we can help to create that culture, as well as benefiting from it. |
| 8106 | In raising a child we must think of his old age [Joubert] |
| Full Idea: In raising a child we must think of his old age. | |
| From: Joseph Joubert (Notebooks [1800], 1809) | |
| A reaction: Very nice, and Aristotle would approve. If educators think much about the future, it rarely extends before the child's first job. We should be preparing good grand-parents, as well as parents and employees. Educate for retirement! |
| 8105 | We can't exactly conceive virtue without the idea of God [Joubert] |
| Full Idea: If we exclude the idea of God, it is impossible to have an exact idea of virtue. | |
| From: Joseph Joubert (Notebooks [1800], 1808) | |
| A reaction: I suspect that an 'exact' idea is impossible even with an idea of God. This is an interesting defence of the importance of God in moral thinking, but it only requires the concept of a supreme being, and not belief. |
| 8102 | We cannot speak against Christianity without anger, or speak for it without love [Joubert] |
| Full Idea: We cannot speak against Christianity without anger, or speak for it without love. | |
| From: Joseph Joubert (Notebooks [1800], 1801) | |
| A reaction: This seems to be rather true at the present time, when a wave of anti-religious books is sweeping through our culture. Presumably this remark used to be true of ancient paganism, but it died away. Christianity, though, is very personal. |