23 ideas
| 10688 | 'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall] |
| Full Idea: 'Equivocation' is when the terms do not mean the same thing in the premises and in the conclusion. | |
| From: JC Beall / G Restall (Logical Consequence [2005], Intro) |
| 10690 | Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall] |
| Full Idea: Logic is purely formal either when it is invariant under permutation of object (Tarski), or when it has totally abstracted away from all contents, or it is the constitutive norms for thought. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 2) | |
| A reaction: [compressed] The third account sounds rather woolly, and the second one sounds like a tricky operation, but the first one sounds clear and decisive, so I vote for Tarski. |
| 10691 | Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall] |
| Full Idea: Technical work on logical consequence has either focused on proofs, where validity is the existence of a proof of the conclusions from the premises, or on models, which focus on the absence of counterexamples. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 3) |
| 10695 | Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall] |
| Full Idea: Two different views of logical consequence are necessary truth-preservation (based on modelling possible worlds; favoured by Realists), or truth-preservation based on the meanings of the logical vocabulary (differing in various models; for Anti-Realists). | |
| From: JC Beall / G Restall (Logical Consequence [2005], 2) | |
| A reaction: Thus Dummett prefers the second view, because the law of excluded middle is optional. My instincts are with the first one. |
| 10689 | A step is a 'material consequence' if we need contents as well as form [Beall/Restall] |
| Full Idea: A logical step is a 'material consequence' and not a formal one, if we need the contents as well as the structure or form. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 2) |
| 10696 | A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall] |
| Full Idea: If a conclusion follows from an empty collection of premises, it is true by logic alone, and is a 'logical truth' (sometimes a 'tautology'), or, in the proof-centred approach, 'theorems'. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 4) | |
| A reaction: These truths are written as following from the empty set Φ. They are just implications derived from the axioms and the rules. |
| 10693 | Models are mathematical structures which interpret the non-logical primitives [Beall/Restall] |
| Full Idea: Models are abstract mathematical structures that provide possible interpretations for each of the non-logical primitives in a formal language. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 3) |
| 10692 | Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall] |
| Full Idea: There are many proof-systems, the main being Hilbert proofs (with simple rules and complex axioms), or natural deduction systems (with few axioms and many rules, and the rules constitute the meaning of the connectives). | |
| From: JC Beall / G Restall (Logical Consequence [2005], 3) |
| 19555 | People begin to doubt whether they 'know' when the answer becomes more significant [Conee] |
| Full Idea: Fluent speakers typically become increasingly hesitant about 'knowledge' attributions as the practical significance of the right answer increases. | |
| From: Earl Conee (Contextualism Contested (and reply) [2005], 'Epistemic') | |
| A reaction: The standard examples of this phenomenon are in criminal investigations, and in philosophical discussions of scepticism. Simple observations I take to have maximum unshakable confidence, except in extreme global scepticism contexts. |
| 19557 | Maybe low knowledge standards are loose talk; people will deny that it is 'really and truly' knowledge [Conee] |
| Full Idea: Maybe variable knowledge ascriptions are just loose talk. This is shown when we ask whether weakly supported knowledge is 'really' or 'truly' or 'really and truly' known. Fluent speakers have a strong inclination to doubt or deny that it is. | |
| From: Earl Conee (Contextualism Contested (and reply) [2005], 'Loose') | |
| A reaction: [bit compressed] Conee is suggesting the people are tacitly invariantist about knowledge (they have a fixed standard). But it may be that someone who asks 'do you really and truly know?' is raising the contextual standard. E.g. a barrister. |
| 19556 | Maybe knowledge has fixed standards (high, but attainable), although people apply contextual standards [Conee] |
| Full Idea: It may be that all 'knowledge' attributions have the same truth conditions, but people apply contextually varying standards. The most plausible standard for truth is very high, but not unreachably high. | |
| From: Earl Conee (Contextualism Contested (and reply) [2005], 'Loose') | |
| A reaction: This is the 'invariantist' alternative to contextualism about knowledge. Is it a standard 'for truth'? Either it is or it isn't true, so there isn't a standard. I take the standard to concern the justification. |
| 4608 | Minds are hard-wired, or trial-and-error, or experimental, or full self-aware [Dennett, by Heil] |
| Full Idea: Dennett identifies a hierarchy of minds running from 'Darwinian' (hard-wired solutions to problems), to 'Skinnerian' (trial-and-error), to 'Popperian' (anticipating possible experience), to 'Gregorian' (self-conscious representation, probably linguistic). | |
| From: report of Daniel C. Dennett (Kinds of Minds [1996]) by John Heil - Philosophy of Mind Ch.5 | |
| A reaction: Interesting. The concept of an experiment seems a major step (assessing reality against an internal map), and the ability to think about one's own thoughts certainly strikes me as the mark of a top level mind. Maybe that is the importance of language. |
| 4880 | Sentience comes in grades from robotic to super-human; we only draw a line for moral reasons [Dennett] |
| Full Idea: 'Sentience' comes in every imaginable grade or intensity, from the simplest and most 'robotic', to the most exquisitely sensitive, hyper-reactive 'human'. We have to draw a line for moral policy, but it is unlikely we will ever discover a threshold. | |
| From: Daniel C. Dennett (Kinds of Minds [1996], Ch.4) | |
| A reaction: This is the only plausible view, if you take the theory of evolution seriously. We can even observe low-grade marginal sentience in our own minds, and then shoot up the scale when we focus our minds properly on an object. |
| 4873 | What is it like to notice an uncomfortable position when you are asleep? [Dennett] |
| Full Idea: What is it like to notice, while sound asleep, that your left arm has become twisted into a position in which it is putting undue strain on your left shoulder? Like nothing. | |
| From: Daniel C. Dennett (Kinds of Minds [1996], Ch.1) | |
| A reaction: A nice question, and all part of Dennett's accurate campaign to show that consciousness is not an all-or-nothing thing. As when we are barely aware of driving, innumerable things happen in the shadowy corners of thought. |
| 4881 | Being a person must involve having second-order beliefs and desires (about beliefs and desires) [Dennett] |
| Full Idea: An important step towards becoming a person is the step up from a first-order intentional system to a second-order system (which has beliefs and desires about beliefs and desires). | |
| From: Daniel C. Dennett (Kinds of Minds [1996], Ch.5) | |
| A reaction: Call it 'meta-thought'. I agree. Dennett thinks language is crucial to this, but the hallmark of intelligence and full-blown personhood is meta- and meta-meta-thought. Maybe the development of irony is a step up the evolutionary scale. Sarcasm is GOOD. |
| 4875 | We descend from robots, and our intentionality is composed of billions of crude intentional systems [Dennett] |
| Full Idea: We are descended from robots, and composed of robots, and all the intentionality we enjoy is derived from the more fundamental intentionality of billions of crude intentional systems. | |
| From: Daniel C. Dennett (Kinds of Minds [1996], Ch.2) | |
| A reaction: A more grand view of intentionality (such as Searle's) seems more attractive than this, but the crucial fact about Dennett is that he takes the implications of evolution much more seriously than other philosophers. He's probably right. |
| 4879 | There is no more anger in adrenaline than silliness in a bottle of whiskey [Dennett] |
| Full Idea: There is no more fear or anger in adrenaline than there is silliness in a bottle of whiskey. | |
| From: Daniel C. Dennett (Kinds of Minds [1996], Ch.3) | |
| A reaction: Not exactly an argument, but a nice rhetorical point against absurd claims about identity and reduction and elimination. We may say that there is no fear without adrenaline, and no adrenaline in a live brain without fear. |
| 4876 | Maybe there is a minimum brain speed for supporting a mind [Dennett] |
| Full Idea: Perhaps there is a minimum speed for a mind, rather like the minimum escape velocity required to overcome gravity and leave the planet. | |
| From: Daniel C. Dennett (Kinds of Minds [1996], Ch.3) | |
| A reaction: Dennett rejects this speculation, but he didn't stop to imagine what it would be LIKE if your brain slowed down, and he never considers Edelman's view that mind is a process. Put the two together… |
| 4878 | The materials for a mind only matter because of speed, and a need for transducers and effectors [Dennett] |
| Full Idea: I think there are only two good reasons why, when you make a mind, the materials matter: speed, and the ubiquity of transducers and effectors throughout the nervous system. | |
| From: Daniel C. Dennett (Kinds of Minds [1996], Ch.3) | |
| A reaction: This sounds roughly right, because it gives you something between multiple realisability (minds made of cans and string), and type-type identity (minds ARE a particular material). Call it 'biological functionalism'? |
| 4874 | The predecessor and rival of the language of thought hypothesis is the picture theory of ideas [Dennett] |
| Full Idea: The ancestor and chief rival of the language-of-thought hypothesis is the picture theory of ideas - that thoughts are about what they are about because they resemble their objects. | |
| From: Daniel C. Dennett (Kinds of Minds [1996], Ch.2) | |
| A reaction: When you place them side by side, neither seems quite right. How can a mental state resemble an object, and how can an inner language inherently capture the features of an object? Maybe we lack the words for the correct theory. |
| 4882 | Concepts are things we (unlike dogs) can think about, because we have language [Dennett] |
| Full Idea: A dog cannot consider its concepts. Concepts are not things in a dog's world in the way that cats are. Concepts are things in our world, because we have language. | |
| From: Daniel C. Dennett (Kinds of Minds [1996], Ch.6) | |
| A reaction: Dogs must have concepts, though, or much of their behaviour (like desperation to go for a walk, or to eat) is baffling. This is as good a proposal as I have ever encountered for the value of language. Meta-thought is a huge evolutionary advantage. |
| 4872 | Most people see an abortion differently if the foetus lacks a brain [Dennett] |
| Full Idea: If a fetus that is being considered for abortion is known to be anencephalic (lacking a brain), this dramatically changes the issue for most people, though not for all. | |
| From: Daniel C. Dennett (Kinds of Minds [1996], Ch.1) | |
| A reaction: A very effective point, as it is hard to see what grounds could be given for not aborting in this case. But the brain then clearly becomes the focus of why abortion is often rejected by many people. |
| 4877 | Maybe plants are very slow (and sentient) animals, overlooked because we are faster? [Dennett] |
| Full Idea: Might plants just be 'very slow animals', enjoying sentience that has been overlooked by us because of our human timescale chauvinism? | |
| From: Daniel C. Dennett (Kinds of Minds [1996], Ch.3) | |
| A reaction: Delightful thought, arising from pondering the significance of the speed of operation of the brain. I think it is false, because I think high speed is essential to mind, and Dennett seems not to. |