37 ideas
19066 | Philosophy aims to understand the world, through ordinary experience and science [Dummett] |
Full Idea: Philosophy is an attempt to understand the world, as it is revealed to us both in our ordinary experience and by the discoveries and theories of science. | |
From: Michael Dummett (The Justification of Deduction [1973], p.311) | |
A reaction: I don't see a sharp division between 'ordinary' and 'scientific'. I really like this idea, first because it makes 'understanding' central, and second because it wants both revelations. In discussing matter and time, there is too much emphasis on science. |
19067 | A successful proof requires recognition of truth at every step [Dummett] |
Full Idea: For a demonstration to be cogent it is necessary that the passage from step to step involve a recognition of truth at each line. | |
From: Michael Dummett (The Justification of Deduction [1973], p.313) | |
A reaction: Dummett cited Quine (esp. 1970) as having an almost entirely syntactic view of logic. Rumfitt points out that logic can move validly from one falsehood to another. Even a 'proof' might detour into falsehood, but it would not be a 'canonical' proof! |
19060 | Truth-tables are dubious in some cases, and may be a bad way to explain connective meaning [Dummett] |
Full Idea: It is arguable whether two-valued truth tables give correct meanings for certain sentential operators, and even whether they constitute legitimate explanations of any possible sentential operators. | |
From: Michael Dummett (The Justification of Deduction [1973], p.294) | |
A reaction: See 'Many-valued logic' for examples of non-binary truth tables. Presumably logicians should aspire to make their semantics precise, as well as their syntax. |
6548 | Physicalism requires the naturalisation or rejection of set theory [Lycan] |
Full Idea: Eventually set theory will have to be either naturalised or rejected, if a thoroughgoing physicalism is to be maintained. | |
From: William Lycan (Consciousness [1987], 8.4) | |
A reaction: Personally I regard Platonism as a form of naturalism (though a rather bold and dramatic one). The central issue seems to be the ability of the human main/brain to form 'abstract' notions about the physical world in which it lives. |
11066 | Deduction is justified by the semantics of its metalanguage [Dummett, by Hanna] |
Full Idea: For Dummett the semantics of the metalanguage is the external and objective source of the justification of deduction. | |
From: report of Michael Dummett (The Justification of Deduction [1973]) by Robert Hanna - Rationality and Logic 3.4 | |
A reaction: This is offered as an answer to the Lewis Carroll problem that justifying deduction seems to need deduction, thus leading to a regress. [There is a reply to Dummett by Susan Haack] |
19058 | Syntactic consequence is positive, for validity; semantic version is negative, with counterexamples [Dummett] |
Full Idea: A plausible account is that the syntactic notion of consequence is for positive results, that some form of argument is valid; the semantic notion is required for negative results, that some argument is invalid, because a counterexample can be found. | |
From: Michael Dummett (The Justification of Deduction [1973], p.292) | |
A reaction: This rings true for the two strategies of demonstration, the first by following the rules in steps, the second by using your imagination (or a tableau) to think up problems. |
19063 | Beth trees show semantics for intuitionistic logic, in terms of how truth has been established [Dummett] |
Full Idea: Beth trees give a semantics for intuitionistic logic, by representing sentence meaning in terms of conditions under which it is recognised to have been established as true. | |
From: Michael Dummett (The Justification of Deduction [1973], p.305) |
19059 | In standard views you could replace 'true' and 'false' with mere 0 and 1 [Dummett] |
Full Idea: Nothing is lost, on this view, if in the standard semantic treatment of classical sentential logic, we replace the standard truth-values 'true' and 'false' by the numbers 0 and 1. | |
From: Michael Dummett (The Justification of Deduction [1973], p.294) | |
A reaction: [A long context will explain 'on this view'] He is discussing the relationship of syntactic and semantic consequence, and goes on to criticise simple binary truth-table accounts of connectives. Semantics on a computer would just be 0 and 1. |
19062 | Classical two-valued semantics implies that meaning is grasped through truth-conditions [Dummett] |
Full Idea: The standard two-valued semantics for classical logic involves a conception under which to grasp the meaning of a sentence is to apprehend the conditions under which it is, or is not, true. | |
From: Michael Dummett (The Justification of Deduction [1973], p.305) | |
A reaction: The idea is that you only have to grasp the truth tables for sentential logic, and that needs nothing more than knowing whether a sentence is true or false. I'm not sure where the 'conditions' creep in, though. |
19065 | Soundness and completeness proofs test the theory of meaning, rather than the logic theory [Dummett] |
Full Idea: A proof of soundess or completeness is a test, not so much of the logical theory to which it applies, but of the theory of meaning which underlies the semantics. | |
From: Michael Dummett (The Justification of Deduction [1973], p.310) | |
A reaction: These two types of proof concern how the syntax and the semantics match up, so this claim sounds plausible, though I tend to think of them as more like roadworthiness tests for logic, checking how well they function. |
6532 | Types cannot be reduced, but levels of reduction are varied groupings of the same tokens [Lycan] |
Full Idea: If types cannot be reduced to more physical levels, this is not an embarrassment, as long as our institutional categories, our physiological categories, and our physical categories are just alternative groupings of the same tokens. | |
From: William Lycan (Consciousness [1987], 4.3) | |
A reaction: This is a self-evident truth about a car engine, so I don't see why it wouldn't apply equally to a brain. Lycan's identification of the type as the thing which cannot be reduced seems a promising explanation of much confusion among philosophers. |
6531 | Institutions are not reducible as types, but they are as tokens [Lycan] |
Full Idea: Institutional types are irreducible, though I assume that institutional tokens are reducible in the sense of strict identity, all the way down to the subatomic level. | |
From: William Lycan (Consciousness [1987], 4.3) | |
A reaction: This seems a promising distinction, as the boundaries of 'institutions' disappear when you begin to reduce them to lower levels (cf. Idea 4601), and yet plenty of institutions are self-evidently no more than physics. Plants are invisible as physics. |
6534 | One location may contain molecules, a metal strip, a key, an opener of doors, and a human tragedy [Lycan] |
Full Idea: One space-time slice may be occupied by a collection of molecules, a metal strip, a key, an allower of entry to hotel rooms, a facilitator of adultery, and a destroyer souls. | |
From: William Lycan (Consciousness [1987], 4.3) | |
A reaction: Desdemona's handkerchief is a nice example. This sort of remark seems to be felt by some philosophers to be heartless wickedness, and yet it so screamingly self-evident that it is impossible to deny. |
6529 | I see the 'role'/'occupant' distinction as fundamental to metaphysics [Lycan] |
Full Idea: I see the 'role'/'occupant' distinction as fundamental to metaphysics. | |
From: William Lycan (Consciousness [1987], 4.0) | |
A reaction: A passing remark in a discussion of functionalism about the mind, but I find it appealing. Causation is basic to materialistic metaphysics, and it creates networks of regular causes. It leaves open the essentialist question of WHY it has that role. |
6549 | I think greenness is a complex microphysical property of green objects [Lycan] |
Full Idea: Personally I favour direct realism regarding secondary qualities, and identify greenness with some complex microphysical property exemplified by green physical objects. | |
From: William Lycan (Consciousness [1987], 8.4) | |
A reaction: He cites D.M.Armstrong (1981) as his source. Personally I find this a bewildering proposal. Does he think there is greenness in grass AS WELL AS the emission of that wavelength of electro-magnetic radiation? Is greenness zooming through the air? |
19061 | An explanation is often a deduction, but that may well beg the question [Dummett] |
Full Idea: An explanation is often a deductive argument, with the fact needing explaining as its conclusion. ...But the conclusion is usually given in advance, and we may only believe the premisses because they plausibly explain the conclusion. | |
From: Michael Dummett (The Justification of Deduction [1973], p.296) | |
A reaction: [compressed (Dummett's wordy prose cries out for it!)] I suppose this works better in mathematics, which is central to Dummett's interests. In the real world the puzzle is not usually logically implied by its explanation. |
6543 | Intentionality comes in degrees [Lycan] |
Full Idea: Intentionality comes in degrees. | |
From: William Lycan (Consciousness [1987], 5.4) | |
A reaction: I agree. A footprint is 'about' a foot, in the sense of containing concentrated information about it. Can we, though, envisage a higher degree than human thought? Is there a maximum degree? Everything is 'about' everything, in some respect. |
6537 | Teleological views allow for false intentional content, unlike causal and nomological theories [Lycan] |
Full Idea: The teleological view begins to explain intentionality, and in particular allows brain states and events to have false intentional content; causal and nomological theories of intentionality tend to falter on this last task. | |
From: William Lycan (Consciousness [1987], 4.4) | |
A reaction: Certainly if you say thought is 'caused' by the world, false thought become puzzling. I'm not sure I understand the rest of this, but it is an intriguing remark about a significant issue… |
6546 | Pain is composed of urges, desires, impulses etc, at different levels of abstraction [Lycan] |
Full Idea: Our phenomenal experience of pain has components - it is a complex, consisting (perhaps) of urges, desires, impulses, and beliefs, probably occurring at quite different levels of institutional abstraction. | |
From: William Lycan (Consciousness [1987], 5.5) | |
A reaction: This seems to be true, and offers the reductionist a strategy for making inroads into the supposed irreducable and fundamental nature of qualia. What's it like to be a complex hierarchically structured multi-functional organism? |
6547 | The right 'level' for qualia is uncertain, though top (behaviourism) and bottom (particles) are false [Lycan] |
Full Idea: It is just arbitrary to choose a level of nature a priori as the locus of qualia, even though we can agree that high levels (such as behaviourism) and low-levels (such as the subatomic) can be ruled out as totally improbable. | |
From: William Lycan (Consciousness [1987], 5.6) | |
A reaction: Very good. People scream 'qualia!' whenever the behaviour level or the atomic level are proposed as the locations of the mind, but the suggestion that they are complex, and are spread across many functional levels in the middle sounds good. |
6527 | If energy in the brain disappears into thin air, this breaches physical conservation laws [Lycan] |
Full Idea: By interacting causally, Cartesian dualism seems to violate the conservation laws of physics (concerning matter and energy). This seems testable, and afferent and efferent pathways disappearing into thin air would suggest energy is not conserved. | |
From: William Lycan (Consciousness [1987], 1.1) | |
A reaction: It would seem to be no problem as long as outputs were identical in energy to inputs. If the experiment could actually be done, the result might astonish us. |
6528 | In lower animals, psychology is continuous with chemistry, and humans are continuous with animals [Lycan] |
Full Idea: Evolution has proceeded in all other known species by increasingly complex configurations of molecules and organs, which support primitive psychologies; our human psychologies are more advanced, but undeniably continuous with lower animals. | |
From: William Lycan (Consciousness [1987], 1.1) | |
A reaction: Personally I find the evolution objection to dualism highly persuasive. I don't see how anyone can take evolution seriously and be a dualist. If there is a dramatic ontological break at some point, a plausible reason would be needed for that. |
6554 | Two behaviourists meet. The first says,"You're fine; how am I?" [Lycan] |
Full Idea: Old joke: two Behaviourists meet in the street, and the first says,"You're fine; how am I?" | |
From: William Lycan (Consciousness [1987], n1.6) | |
A reaction: This invites the response that introspection is uniquely authoritative about 'how we are', but this has been challenged quite a lot recently, which pushes us to consider whether these stupid behaviourists might actually have a good point. |
6545 | If functionalism focuses on folk psychology, it ignores lower levels of function [Lycan] |
Full Idea: 'Analytical functionalists', who hold that meanings of mental terms are determined by the causal roles associated with them by 'folk psychology', deny themselves appeals to lower levels of functional organisation. | |
From: William Lycan (Consciousness [1987], 5.4) | |
A reaction: Presumably folk psychology can fit into the kind of empirical methodology favoured by behaviourists, whereas 'lower levels' are going to become rather speculative and unscientific. |
6541 | Functionalism must not be too abstract to allow inverted spectrum, or so structural that it becomes chauvinistic [Lycan] |
Full Idea: The functionalist must find a level of characterisation of mental states that is not so abstract or behaviouristic as to rule out the possibility of inverted spectrum etc., nor so specific and structural as to fall into chauvinism. | |
From: William Lycan (Consciousness [1987], 5.4) | |
A reaction: If too specific then animals and aliens won't be able to implement the necessary functions; if the theory becomes very behaviouristic, then it loses interest in the possibility of an inverted spectrum. He is certainly right to hunt for a middle ground. |
6539 | The distinction between software and hardware is not clear in computing [Lycan] |
Full Idea: Even the software/hardware distinction as it is literally applied within computer science is philosophically unclear. | |
From: William Lycan (Consciousness [1987], 4.4) | |
A reaction: This is true, and very important for functionalist theories of the mind. Even very volatile software is realised in 'hard' physics, and rewritable discs etc blur the distinction between 'programmable' and 'hardwired'. |
6535 | Teleological characterisations shade off smoothly into brutely physical ones [Lycan] |
Full Idea: Highly teleological characterisations, unlike naïve and explicated mental characterisations, have the virtue of shading off fairly smoothly into (more) brutely physical ones. | |
From: William Lycan (Consciousness [1987], 4.3) | |
A reaction: Thus the purpose of a car engine, and a spark plug, and the spark, and the temperature, and the vibration of molecules show a fading away of the overt purpose, disappearing into the pointless activity of electrons and quantum levels. |
6533 | Mental types are a subclass of teleological types at a high level of functional abstraction [Lycan] |
Full Idea: I am taking mental types to form a small subclass of teleological types occurring for the most part at a high level of functional abstraction. | |
From: William Lycan (Consciousness [1987], 4.3) | |
A reaction: He goes on to say that he understand teleology in evolutionary terms. There is always a gap between how you characterise or individuate something, and what it actually is. To say spanners are 'a small subclass of tools' is not enough. |
6544 | Identity theory is functionalism, but located at the lowest level of abstraction [Lycan] |
Full Idea: 'Neuron' may be understood as a physiological term or a functional term, so even the Identity Theorist is a Functionalist - one who locates mental entities at a very low level of abstraction. | |
From: William Lycan (Consciousness [1987], 5.4) | |
A reaction: This is a striking observation, and somewhat inclines me to switch from identity theory to functionalism. If you ask what is the correct level of abstraction, Lycan's teleological-homuncular version refers you to all the levels. |
6536 | Teleological functionalism helps us to understand psycho-biological laws [Lycan] |
Full Idea: Teleological functionalism helps us to understand the nature of biological and psychological laws, particularly in the face of Davidsonian scepticism about the latter. | |
From: William Lycan (Consciousness [1987], 4.4) | |
A reaction: Personally I doubt the existence of psycho-physical laws, but only because of the vast complexity. They would be like the laws of weather. 'Psycho-physical' laws seem to presuppose some sort of dualism. |
6530 | We reduce the mind through homuncular groups, described abstractly by purpose [Lycan] |
Full Idea: I am explicating the mental in a reductive way, by reducing mental characterizations to homuncular institutional ones, which are teleological characterizations at various levels of functional abstraction. | |
From: William Lycan (Consciousness [1987], 4.3) | |
A reaction: I think this is the germ of a very good physicalist account of the mind. More is needed than a mere assertion about what the mind reduces to at the very lowest level; this offers a decent account of the descending stages of reduction. |
6542 | A Martian may exhibit human-like behaviour while having very different sensations [Lycan] |
Full Idea: Quite possibly a Martian's humanoid behaviour is prompted by his having sensations somewhat unlike ours, despite his superficial behavioural similarities to us. | |
From: William Lycan (Consciousness [1987], 5.4) | |
A reaction: I think this firmly refutes the multiple realisability objection to type-type physicalism. Mental events are individuated by their phenomenal features (known only to the user), and by their causal role (publicly available). These are separate. |
19064 | Holism is not a theory of meaning; it is the denial that a theory of meaning is possible [Dummett] |
Full Idea: In the sense of giving a model for the content of a sentence, its representative power, holism is not a theory of meaning; it is the denial that a theory of meaning is possible. | |
From: Michael Dummett (The Justification of Deduction [1973], p.309) | |
A reaction: This will obviously be because sentences just don't have meaning in isolation, so their meaning can't be given in terms of the sentences. |
5121 | Basing ethics on flourishing makes it consequentialist, as actions are judged by contributing to it [Harman] |
Full Idea: Basing ethics on human flourishing tends towards utilitarianism or consequentialism; actions, character traits, laws, and so on are to be assessed with reference to their contributions to human flourishing. | |
From: Gilbert Harman (Human Flourishing, Ethics and Liberty [1983], 9.2.2) | |
A reaction: This raises the question of whether only virtue can contribute to flourishing, or whether a bit of vice might be helpful. This problem presumably pushed the Stoics to say that virtue itself is the good, rather than the resulting flourishing. |
5120 | What counts as 'flourishing' must be relative to various sets of values [Harman] |
Full Idea: If we base our ethics on human flourishing, one implication would seem to be moral relativism, since what counts as 'flourishing' seems inevitably relative to one or other set of values. | |
From: Gilbert Harman (Human Flourishing, Ethics and Liberty [1983], 9.2.1) | |
A reaction: This remark seems to make the relativist assumption that all value systems are equal. For Aristotle, flourishing is no more relative than health is. No one can assert that illness has an intrinsically high value in human life. |
6538 | We need a notion of teleology that comes in degrees [Lycan] |
Full Idea: We need a notion of teleology that comes in degrees. | |
From: William Lycan (Consciousness [1987], 4.4) | |
A reaction: Anyone who says that key concepts, such as those concerning the mind, should come 'in degrees' wins my instant support. A whole car engine requires a very teleological explanation, the spark in the sparkplug far less so. |
6551 | 'Physical' means either figuring in physics descriptions, or just located in space-time [Lycan] |
Full Idea: An object is specifically physical if it figures in explanations and descriptions of features of ordinary non-living matter, as in current physics; it is more generally physical if it is simply located in space-time. | |
From: William Lycan (Consciousness [1987], 8.5) | |
A reaction: This gives a useful distinction when trying to formulate a 'physicalist' account of the mind, where type-type physicalism says only the 'postulates of physics' can be used, whereas 'naturalism' about the mind uses the more general concept. |