30 ideas
21461 | I tried to be unsystematic and piecemeal, but failed; my papers presuppose my other views [Lewis] |
Full Idea: I should have like to be a piecemeal, unsystematic philosopher, offering independent proposals on a variety of topics. It was not be. I succumbed too often to the temptation to presuppose my views on one topic when writing on another. | |
From: David Lewis (Introduction to Philosophical Papers I [1983], p.1) | |
A reaction: He particularly mentions his possible worlds realism as a doctrine which coloured all his other work. A charming insight into the mind of a systematic thinker (called by someone 'the most systematic metaphysician since Leibniz'). |
8952 | We reach 'reflective equilibrium' when intuitions and theory completely align [Fisher] |
Full Idea: A state of 'reflective equilibrium' is when our theory and our intuitions become completely aligned | |
From: Jennifer Fisher (On the Philosophy of Logic [2008], 12.IV) | |
A reaction: [Rawls made this concept famous] This is a helpful concept in trying to spell out the ideal which is the dream of believers in 'pure reason' - that there is a goal in which everything comes right. The problem is when people have different intuitions! |
8943 | Three-valued logic says excluded middle and non-contradition are not tautologies [Fisher] |
Full Idea: In three-valued logic (L3), neither the law of excluded middle (p or not-p), nor the law of non-contradiction (not(p and not-p)) will be tautologies. If p has the value 'indeterminate' then so will not-p. | |
From: Jennifer Fisher (On the Philosophy of Logic [2008], 07.I) | |
A reaction: I quite accept that the world is full of indeterminate propositions, and that excluded middle and non-contradiction can sometimes be uncertain, but I am reluctant to accept that what is being offered here should be called 'logic'. |
8945 | Fuzzy logic has many truth values, ranging in fractions from 0 to 1 [Fisher] |
Full Idea: In fuzzy logic objects have properties to a greater or lesser degree, and truth values are given as fractions or decimals, ranging from 0 to 1. Not-p is defined as 1-p, and other formula are defined in terms of maxima and minima for sets. | |
From: Jennifer Fisher (On the Philosophy of Logic [2008], 07.II) | |
A reaction: The question seems to be whether this is actually logic, or a recasting of probability theory. Susan Haack attacks it. If logic is the study of how truth is preserved as we move between propositions, then 0 and 1 need a special status. |
8951 | Classical logic is: excluded middle, non-contradiction, contradictions imply all, disjunctive syllogism [Fisher] |
Full Idea: For simplicity, we can say that 'classical logic' amounts to the truth of four sentences: 1) either p or not-p; 2) it is not the case that both p and not-p; 3) from p and not-p, infer q; 4) from p or q and not-p, infer q. | |
From: Jennifer Fisher (On the Philosophy of Logic [2008], 12.I) | |
A reaction: [She says there are many ways of specifying classical logic] Intuition suggests that 2 and 4 are rather hard to dispute, while 1 is ignoring some grey areas, and 3 is totally ridiculous. There is, of course, plenty of support for 3! |
8950 | Logic formalizes how we should reason, but it shouldn't determine whether we are realists [Fisher] |
Full Idea: Even if one is inclined to be a realist about everything, it is hard to see why our logic should be the determiner. Logic is supposed to formalize how we ought to reason, but whether or not we should be realists is a matter of philosophy, not logic. | |
From: Jennifer Fisher (On the Philosophy of Logic [2008], 09.I) | |
A reaction: Nice to hear a logician saying this. I do not see why talk in terms of an object is a commitment to its existence. We can discuss the philosopher's stone, or Arthur's sword, or the Loch Ness monster, or gravitinos, with degrees of commitment. |
8946 | We could make our intuitions about heaps precise with a million-valued logic [Fisher] |
Full Idea: We could construct a 1,000,000-valued logic that would allow our intuitions concerning a heap to vary exactly with the amount of sand in the heap. | |
From: Jennifer Fisher (On the Philosophy of Logic [2008]) | |
A reaction: Presumably only an infinite number of grains of sand would then produce a true heap, and even one grain would count as a bit of a heap, which must both be wrong, so I can't see this helping much. |
4913 | Brain lesions can erase whole categories of perception, suggesting they are hard-wired [Carter,R] |
Full Idea: The discovery that a single brain lesion can erase all knowledge of man-made artefacts, or all knowledge of animals, suggests that these categories somehow hard-wired into the brain - that we all have a set of 'memory pigeonholes'. | |
From: Rita Carter (Mapping the Mind [1998], p.190) | |
A reaction: Presumably something can become 'hard-wired' through experience, rather than from birth. The whole idea of 'hard-wired' seems misleading about the brain. What matters is that the brain physically constructs categories. |
8944 | Vagueness can involve components (like baldness), or not (like boredom) [Fisher] |
Full Idea: Vague terms come in at least two different kinds: those whose constituent parts come in discrete packets (bald, rich, red) and those that don't (beauty, boredom, niceness). | |
From: Jennifer Fisher (On the Philosophy of Logic [2008], 07.II) | |
A reaction: The first group seem to be features of the external world, and the second all occur in the mind. Baldness may be vague, but presumably hairs are (on the whole) not. Nature doesn't care whether someone is actually 'bald' or not. |
8941 | We can't explain 'possibility' in terms of 'possible' worlds [Fisher] |
Full Idea: Explaining 'it is possible that p' by saying p is true in at least one possible world doesn't get me very far. If I don't understand what possibility is, then appealing to possible worlds is not going to do me much good. | |
From: Jennifer Fisher (On the Philosophy of Logic [2008], 06.III) | |
A reaction: This seems so blatant that I assume friends of possible worlds will have addressed the problem. Note that you will also need to understand 'possible' to define necessity as 'true in all possible worlds'. Necessarily-p is not-possibly-not-p. |
8947 | If all truths are implied by a falsehood, then not-p might imply both q and not-q [Fisher] |
Full Idea: If all truths are implied by a falsehood, then 'if there are no trees in the park then there is no shade' and 'if there are no trees in the park there is plenty of shade' both come out as true. Intuitively, though, the second one is false. | |
From: Jennifer Fisher (On the Philosophy of Logic [2008], 08.I) | |
A reaction: The rule that a falsehood implies all truths must be the weakest idea in classical logic, if it actually implies a contradiction. This means we must take an interest in relevance logics. |
8949 | In relevance logic, conditionals help information to flow from antecedent to consequent [Fisher] |
Full Idea: A good account of relevance logic suggests that a conditional will be true when the flow of information is such that a conditional is the device that helps information to flow from the antecedent to the consequent. | |
From: Jennifer Fisher (On the Philosophy of Logic [2008], 08.III) | |
A reaction: Hm. 'If you are going out, you'll need an umbrella'. This passes on information about 'out', but also brings in new information. 'If you are going out, I'm leaving you'. What flows is an interpretation of the antecedent. Tricky. |
4910 | Sense organs don't discriminate; they reduce various inputs to the same electrical pulses [Carter,R] |
Full Idea: Despite their variety, each sense organ translates its stimulus into electrical pulses; rather than discriminating one type of input from another, the sense organs actually make them more alike. | |
From: Rita Carter (Mapping the Mind [1998], p.174) | |
A reaction: An illuminating observation, which modern 'naïve realists' should bear in mind. Secondary qualities are entirely unrelated to the nature of the input, and are merely 'what the brain decides to make of it'. Discrimination is in our neurons. |
4911 | The recognition sequence is: classify, name, locate, associate, feel [Carter,R, by PG] |
Full Idea: The sequence of events in the brain for perceptual recognition is first identifying a rough class for the object, then a name, then a location, then some associations, and finally an emotion. | |
From: report of Rita Carter (Mapping the Mind [1998], p.181) by PG - Db (ideas) | |
A reaction: This seems to be one of those places where neuro-science trumps philosophy. You can't argue with empirical research, so philosophical theories had better adapt themselves to this sequence. The big modern discovery is the place of emotion in recognition. |
4919 | There seems to be no dividing line between a memory and a thought [Carter,R] |
Full Idea: It has become clear from research that there is no clear dividing line between a memory and a thought. | |
From: Rita Carter (Mapping the Mind [1998], p.308) | |
A reaction: This always struck me as an obvious criticism of Descartes, when he claimed that memory was not an essential part of the 'thinking thing'. How can you think or understand without memory of the different phases of your thoughts? No memory, no mind! |
4908 | No one knows if animals are conscious [Carter,R] |
Full Idea: No one knows if animals are conscious. | |
From: Rita Carter (Mapping the Mind [1998], p.155) | |
A reaction: This is a report from the front line of brain research, and should be born in mind when over-confident people make pronouncements about this topic. It strikes me as important to grasp that animals MIGHT not be conscious. |
4902 | Pain doesn't have one brain location, but is linked to attention and emotion [Carter,R] |
Full Idea: Scans show there is no such thing as a pain centre; pain springs mainly from the activation of areas associated with attention and emotion. | |
From: Rita Carter (Mapping the Mind [1998], p. 12) | |
A reaction: Most brain research points to the complex multi-layered nature of experiences that were traditionally considered simple. We can be distracted from a pain, and an enormous number of factors can affect our degree of dislike of a given pain. |
4915 | In primates, brain size correlates closely with size of social group [Carter,R] |
Full Idea: Brain size in primates is closely associated with the size of the social group in which the animal lives. | |
From: Rita Carter (Mapping the Mind [1998], p.257) | |
A reaction: Intriguing. Humans can have huge social groups because of language, which suggests a chicken-or-egg question. Language, intelligence and size of social group must have expanded together in humans. |
4904 | Proper brains appear at seven weeks, and neonates have as many neurons as adults do [Carter,R] |
Full Idea: The main sections of the brain, including the cerebral cortex, are visible within seven weeks of conception, and by the time the child is born the brain contains as many neurons - about 100 billion - as it will have as an adult. | |
From: Rita Carter (Mapping the Mind [1998], p. 17) | |
A reaction: Of interest in the abortion debate, and also in thinking about personal identity. However, it seems clear that the number of connections, rather than neurons, is what really matters. A small infant may well lack personal identity. |
4917 | Consciousness involves awareness, perception, self-awareness, attention and reflection [Carter,R] |
Full Idea: Awareness, perception, self-awareness, attention and reflection are all separate components of consciousness, and the quality of our experience varies according to which and how many of them are present. | |
From: Rita Carter (Mapping the Mind [1998], p.300) | |
A reaction: Philosophers like to emphasise 'qualia' and 'intentionality'. This remark slices the cake differently. 'Attention' is interesting, dividing consciousness into two areas, with some experience fading away into the darkness. Hume denied self-awareness. |
4916 | There is enormous evidence that consciousness arises in the frontal lobes of the brain [Carter,R] |
Full Idea: A huge volume of evidence suggests that consciousness emerges from the activity of the cerebral cortex, and in particular from the frontal lobes. | |
From: Rita Carter (Mapping the Mind [1998], p.298) | |
A reaction: Dualists must face up to this, and even many physicalists have a rather vague notion about the location of awareness, but we are clearly homing in very precise physical substances which have consciousness as a feature. |
4905 | Normal babies seem to have overlapping sense experiences [Carter,R] |
Full Idea: Connections in a baby's brain probably give the infant the experience of 'seeing' sounds and 'hearing' colours - which occasionally continues into adulthood, where it is known as 'synaesthesia'. | |
From: Rita Carter (Mapping the Mind [1998], p. 19) | |
A reaction: A fact to remember when discussing secondary qualities, and the relativism involved in the way we perceive the world. If you have done your philosophy right, you shouldn't be surprised by this discovery. |
4918 | In blindsight V1 (normal vision) is inactive, but V5 (movement) lights up [Carter,R] |
Full Idea: Scans show that a sub-section of the visual cortex called V5 - the area that registers movement - lights up during blindsight, even though V1 - the primary sensory area that is essential for normal sight - is not active. | |
From: Rita Carter (Mapping the Mind [1998], p.307) | |
A reaction: The whole point of blindsight is to make us realise that vision involves not one module, but a whole team of them. The inference is that V1 involves consciousness, but other areas of the visual cortex don't. |
4912 | Out-of-body experiences may be due to temporary loss of proprioception [Carter,R] |
Full Idea: Out-of-body experiences may be due to temporary loss of proprioception. | |
From: Rita Carter (Mapping the Mind [1998], p.187) | |
A reaction: This is only a speculation, but it is an effect which can be caused by brain injury, and dualists should face the possibility that this evidence (prized by many dualists) can have a physical explanation. |
4903 | Scans of brains doing similar tasks produce very similar patterns of activation [Carter,R] |
Full Idea: The pattern of brain activation during, say, a word retrieval task is usually similar enough among the dozen or so participants who typically take part in such studies for their scans to be overlaid and still show a clear pattern. | |
From: Rita Carter (Mapping the Mind [1998], p. 17) | |
A reaction: This doesn't surprise me, though it could be interpreted as supporting type-type identity, or as supporting functionalism. Armstrong and Lewis endorse a sort of reductive functionalism which would fit this observation. |
4920 | Thinking takes place on the upper side of the prefrontal cortex [Carter,R] |
Full Idea: The nuts and bolts of thinking - holding ideas in mind and manipulating them - takes place on the upper side of the prefrontal cortex. | |
From: Rita Carter (Mapping the Mind [1998], p.312) | |
A reaction: Keep this firmly in view! Imagine that the skull is transparent, and brain activity moves in waves of colour. Dualism would, in those circumstances, never have even occurred to anyone. |
4906 | Babies show highly emotional brain events, but may well be unaware of them [Carter,R] |
Full Idea: Babies show emotion dramatically, but the areas of the brain that in adults are linked to the conscious experience of emotions are not active in newborn babies. Such emotions may therefore be unconscious. | |
From: Rita Carter (Mapping the Mind [1998], p. 19) | |
A reaction: Traditionally, 'unconscious emotion' is a contradiction, but I think we should accept this new evidence and rethink the nature of mind. Not only might emotion be non-conscious, but we should even consider that rational thinking could be too. |
4909 | The only way we can control our emotions is by manipulating the outside world that influences them [Carter,R] |
Full Idea: We try to manipulate our emotions all the time, but all we are doing is arranging the outside world so it triggers certain emotions - we cannot control our reactions directly. | |
From: Rita Carter (Mapping the Mind [1998], p.155) | |
A reaction: This seems to me to throw a very illuminating light on a huge amount of human behaviour, such as going to the cinema or listening to music. The romantic movement encouraged direct internal manipulation. Compare sex fantasies with viewing pornography. |
4914 | A frog will starve to death surrounded by dead flies [Carter,R] |
Full Idea: A frog will starve to death surrounded by dead flies. | |
From: Rita Carter (Mapping the Mind [1998], p.195) | |
A reaction: A nice warning against assuming that rationality is operating when a frog feels hungry and 'decides' to have lunch. We should take comfort from the fact that humans are NOT this stupid, and philosophers should try to accurately describe our gift. |
4907 | The 'locus coeruleus' is one of several candidates for the brain's 'pleasure centre' [Carter,R] |
Full Idea: Noradrenaline is an excitatory chemical that induces physical and mental arousal and heightens mood. Production is centred in an area of the brain called the locus coeruleus, which is one of several candidates for the brain's 'pleasure' centre. | |
From: Rita Carter (Mapping the Mind [1998], p. 30) | |
A reaction: It seems to me very morally desirable that people understand facts of this kind, so that they can be more objective about pleasure. Pleasure is one cog in the machine that makes a person, not the essence of human life. |