26 ideas
| 3123 | Science is in the business of carving nature at the joints [Segal] |
| Full Idea: Science is in the business of carving nature at the joints. | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 5) |
| 15873 | Laws of nature are just records of regularities and correlations, with concepts to make recording them easier [Mach, by Harré] |
| Full Idea: For Mach, the laws of nature are simply the compendious record of sensory regularities, correlations of elements. Any additional concepts are no more than symbols or devices for the convenient recording of general sensory patterns. | |
| From: report of Ernst Mach (Popular Scientific Lectures [1894], pp.201-5) by Rom Harré - Laws of Nature 2 | |
| A reaction: Mach is the high priest of scientific positivism, which is really just hard-line empiricism. |
| 3125 | Psychology studies the way rationality links desires and beliefs to causality [Segal] |
| Full Idea: A person's desires and beliefs tend to cause what they tend to rationalise. This coordination of causality and rationalisation lies at the heart of psychology. | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 5.3) |
| 3105 | Is 'Hesperus = Phosphorus' metaphysically necessary, but not logically or epistemologically necessary? [Segal] |
| Full Idea: It is metaphysically necessary that Hesperus is Phosphorus, but not logically necessary, since logical deduction could not reveal its truth, and it is not epistemologically necessary, as the ancient Greeks didn't know the identity. (Natural necessity?) | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 1.6) |
| 3106 | If claims of metaphysical necessity are based on conceivability, we should be cautious [Segal] |
| Full Idea: Since conceivability is the chief method of assessing the claims of metaphysical necessity, I think such claims are incautious. | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 1.6) |
| 3113 | The success and virtue of an explanation do not guarantee its truth [Segal] |
| Full Idea: The success and virtue of an explanation do not guarantee its truth. | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 2.2) |
| 3112 | Folk psychology is ridiculously dualist in its assumptions [Segal] |
| Full Idea: Commonsense psychology is a powerful explanatory theory, and largely correct, but it seems to be profoundly dualist, and treats minds as immaterial spirits which can transmigrate and exist disembodied. | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 2.2) | |
| A reaction: Fans of folk psychology tend to focus on central normal experience, but folk psychology also seems to range from quirky to barking mad. A 'premonition' is a widely accepted mental event. |
| 3108 | If 'water' has narrow content, it refers to both H2O and XYZ [Segal] |
| Full Idea: My view is that the concepts of both the Earth person and the Twin Earth person refer to BOTH forms of diamonds or water (H2O and XYZ). | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 1.7) | |
| A reaction: Fair enough, though that seems to imply that my current concepts may actually refer to all sorts of items of which I am currently unaware. But that may be so. |
| 3110 | Humans are made of H2O, so 'twins' aren't actually feasible [Segal] |
| Full Idea: Humans are largely made of H2O, so there could be no twin on Twin Earth, and (as Kuhn noted) nothing with a significantly different structure from H2O could be macroscopically very like water (but topaz and citrine will do). | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 2.1) | |
| A reaction: A small point, but one that appeals to essentialists like me (see under Natural Theory/Laws of Nature). We can't learn much metaphysics from impossible examples. |
| 3124 | Externalists can't assume old words refer to modern natural kinds [Segal] |
| Full Idea: The question of what a pre-scientific term extends over is extremely difficult for a Putnam-style externalist to answer. …There seems no good reason to assume that they extend over natural kinds ('whale', 'cat', 'water'). | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 5.1) | |
| A reaction: The assumption seems to be that they used to extend over descriptions, and now they extend over essences, or expert references. This can't be right. They have never changed, but now contain fewer errors. |
| 3117 | Concepts can survive a big change in extension [Segal] |
| Full Idea: We need to think of concepts as organic entities that can persist through changes of extension. | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 3.3) | |
| A reaction: This would be 'organic' in the sense of modifying and growing. This is exactly right, and the interesting problem becomes the extreme cases, where an individual stretches a concept a long way. |
| 3104 | Must we relate to some diamonds to understand them? [Segal] |
| Full Idea: Is a relationship with diamonds necessary for having a concept of diamonds? | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 1.4) | |
| A reaction: Probably not, given that I have a concept of kryptonite, and that I can invent my own concepts. Suppose I was brought up to believe that diamonds are a myth? |
| 3103 | Maybe content involves relations to a language community [Segal] |
| Full Idea: It has been argued (e.g. by Tyler Burge) that certain relations to other language users are determinants of content. | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 1.4) | |
| A reaction: Burge's idea (with Wittgenstein behind him) strikes me as plausible (more plausible than water and elms determining the content). Our concepts actually shift during conversations. |
| 3111 | Externalism can't explain concepts that have no reference [Segal] |
| Full Idea: Empty terms and concepts provide the largest problem for the externalist thesis of the world dependence of concepts. | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 2.2) | |
| A reaction: A speculative concept could then become a reality (e.g. an invention). The solution seems to be to say that there is an internal and an external component to most concepts. |
| 3109 | If content is external, so are beliefs and desires [Segal] |
| Full Idea: If we accept Putnam's externalist conclusion about the meaning of a word, it is a short step to a similar conclusion about the contents of the twins' beliefs, desires and so on. | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 2.1) | |
| A reaction: This is the key step which has launched a whole new externalist view of the nature of the mind. It is one thing to say that I don't quite know what my words mean, another that I don't know my own beliefs. |
| 3116 | Maybe experts fix content, not ordinary users [Segal] |
| Full Idea: Putnam and Burge claim that there could be two words that a misinformed subject uses to express different concepts, but that express just one concept of the experts. | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 3.2) | |
| A reaction: This pushes the concept outside the mind of the user, which leaves an ontological problem of what concepts are made of, how you individuate them, and where they are located. |
| 3121 | If content is narrow, my perfect twin shares my concepts [Segal] |
| Full Idea: To say that contents of my belief are narrow is to say that they are intrinsic to me, hence that any perfect twin of mine would have beliefs with the same contents. | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 5) | |
| A reaction: I personally find this more congenial than externalism. If my twin and I studied chemistry, we would reach identical conclusions about water, as long as we remained perfect twins. |
| 3118 | If thoughts ARE causal, we can't explain how they cause things [Segal] |
| Full Idea: If we identify a psychological property with its causal role then we lose the obvious explanation of why the event has the causal role that it has. | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 4.1) | |
| A reaction: This pinpoints very nicely one of the biggest errors in modern philosophy. There are good naturalistic reasons to reduce everything to causal role, but there is a deeper layer. Essences! |
| 3119 | Even 'mass' cannot be defined in causal terms [Segal] |
| Full Idea: We can't define mass in terms of its causal powers because massive objects do different things in different physical systems. …What an object (or concept) with a given property does depends on what it interacts with. | |
| From: Gabriel M.A. Segal (A Slim Book about Narrow Content [2000], 4.1) | |
| A reaction: This leaves an epistemological problem, that we believe in mass, but can only get at it within a particular gravitational or inertial system. Don't give up on ontology at this point. |
| 22717 | Self-interest can fairly divide a cake; first person cuts, second person chooses [Poundstone] |
| Full Idea: To fairly divide a cake between two children, the first divides it and the second chooses. …Even division is best, as it anticipates the second child will take the largest piece. Fairness is enforced by the children's self-interests. | |
| From: William Poundstone (Prisoner's Dilemma [1992], 03 'Cake') | |
| A reaction: [compressed] This is introduced as the basic principle of game theory. There is an online video of two cats sharing a dish of milk; each one drinks a bit, then pushes the dish to the other one. I'm sure two children could manage that. |
| 22718 | Formal game theory is about maximising or minimising numbers in tables [Poundstone] |
| Full Idea: At the most abstract level, game theory is about tables with numbers in them - numbers that entities are are efficiently acting to maximise or minimise. | |
| From: William Poundstone (Prisoner's Dilemma [1992], 03 'Curve') | |
| A reaction: A brilliant idea. The question is the extent to which real life conforms to the numberical tables. The assumption that everyone is entirely self-seeking is blatantly false. Numbers like money have diminishing marginal utility. |
| 22719 | The minimax theorem says a perfect game of opposed people always has a rational solution [Poundstone] |
| Full Idea: The minimax theorem says that there is always a rational solution to a precisely defined conflict between two people whose interests are completely opposite. | |
| From: William Poundstone (Prisoner's Dilemma [1992], 03 'Minimax') | |
| A reaction: This is Von Neumann's founding theorem of game theory. It concerns maximising minimums, and minimising maximums. Crucially, I would say that it virtually never occurs that two people have completely opposite interests. There is a common good. |
| 22720 | Two prisoners get the best result by being loyal, not by selfish betrayal [Poundstone] |
| Full Idea: Prisoners A and B can support or betray one another. If both support, they each get 1 year in prison. If one betrays, the betrayer gets 0 and the betrayed gets 3. If they both betray they get 2 each. The common good is to support each other. | |
| From: William Poundstone (Prisoner's Dilemma [1992], 06 'Tucker's') | |
| A reaction: [by Albert Tucker, highly compressed] The classic Prisoner's Dilemma. It is artificial, but demonstrates that selfish behaviour gets a bad result (total of four years imprisonment), but the common good gets only two years. Every child should study this! |
| 22721 | The tragedy in prisoner's dilemma is when two 'nice' players misread each other [Poundstone] |
| Full Idea: The tragedy is when two 'nice' players defect because they misread the other's intentions. The puzzle of the prisoner's dilemma is how such good intentions pave the road to hell. | |
| From: William Poundstone (Prisoner's Dilemma [1992], 11 'Howard's') | |
| A reaction: I really wish these simple ideas were better known. They more or less encapsulate the tragedy of the human race, with its inability to prioritise the common good. |
| 22722 | TIT FOR TAT says cooperate at first, then do what the other player does [Poundstone] |
| Full Idea: The successful TIT FOR TAT strategy (for the iterated prisoner's dilemma) says cooperate on the first round, then do whatever the other player did in the previous round. | |
| From: William Poundstone (Prisoner's Dilemma [1992], 12 'TIT') | |
| A reaction: There are also the tougher TWO TITS FOR A TAT, and the more forgiving TIT FOR TWO TATS. The one-for-one seems to be the main winner, and is commonly seen in animal life (apparently). I recommend this to school teachers. |
| 22723 | Do unto others as you would have them do unto you - or else! [Poundstone] |
| Full Idea: TIT FOR TAT threatens 'Do unto others as you would have them do unto you - or else!'. | |
| From: William Poundstone (Prisoner's Dilemma [1992], 12 'TIT') | |
| A reaction: Essentially human happiness arises if we are all nice, but also stand up firmly for ourselves. 'Doormats' (nice all the time) get exploited. TIT FOR TAT is weak, because it doesn't exploit people who don't respond at all. |