112 ideas
| 22246 | A train of reasoning must be treated as all happening simultaneously [Recanati] |
| Full Idea: For logic purposes, a train of reasoning has to be construed as synchronic. | |
| From: François Recanati (Mental Files in Flux [2016], 5.2) | |
| A reaction: If we are looking for a gulf between logic and the real world this is a factor to be considered, along with Nietzsche's observation about necessary simplification. [ref to Kaplan 'Afterthoughts' 1989, 584-5] |
| 16357 | Mental files are the counterparts of singular terms [Recanati] |
| Full Idea: Mental files are the mental counterparts of singular terms. | |
| From: François Recanati (Mental Files [2012], 3.3) | |
| A reaction: A thoroughly satisfactory theory. We can build up a picture of filing merging, duplication, ambiguity, error etc. Eventually neuroscience will map the whole system, and we will have cracked it. |
| 19482 | Current physics says matter and antimatter should have reduced to light at the big bang [New Sci.] |
| Full Idea: Our best theories of physics imply we shouldn't be here. The big bang ought to have produced equal amounts of matter and antimatter particles, which would have almost immediately annihilated each other, leaving nothing but light. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.05.23) | |
| A reaction: This is not, of course, a rejection of physics, but a puzzle about the current standard model of physics. |
| 19483 | CP violation shows a decay imbalance in matter and antimatter, leading to matter's dominance [New Sci.] |
| Full Idea: The phenomenon of charge-parity (CP) violation says that under certain circumstances antiparticles decay at different rates from their matter counterpart. ...This might explain matter's dominance in the universe, but the effect is too small. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.05.23) | |
| A reaction: Physicists are currently studying CP violations, hoping to explain why there is any matter in the universe. This will not, I presume, explain why matter and antimatter arrived in the first place. |
| 16360 | Identity statements are informative if they link separate mental files [Recanati] |
| Full Idea: An identity statement 'A=B' is informative to the extent that the terms 'A' and 'B' are associated with distinct mental files. | |
| From: François Recanati (Mental Files [2012], 4.1) | |
| A reaction: Hence the information in 'Scott is the author of 'Waverley'' is information about what is in your mind, not what is happening in Scotland. This is Recanati's solution to one of Frege's classic puzzles. 'Morning Star' and 'Evening Star' files. Nice. |
| 16374 | There is a continuum from acquaintance to description in knowledge, depending on the link [Recanati] |
| Full Idea: It is not too difficult to imagine a continuum of cases between straightforward instances of knowledge by acquaintance and straightforward instances of knowledge by description, with more or less tenuous informational links to the referent. | |
| From: François Recanati (Mental Files [2012], 12.2) |
| 19737 | A system can infer the structure of the world by making predictions about it [New Sci.] |
| Full Idea: If we can train a system for prediction, it can essentially infer the structure of the world it's looking at by doing this prediction. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.12.12) | |
| A reaction: [AI expert] This seems to be powerful support for the centrality of mathematical laws of nature in achieving understanding of the world. We may downplay the 'mere' ability to predict, but this idea says that the rewards of prediction are very great. |
| 19736 | Neural networks can extract the car-ness of a car, or the chair-ness of a chair [New Sci.] |
| Full Idea: Early neural nets were really good at recognising general categories, such as a car or a chair. Those networks are good at extracting the 'chair-ness' or the 'car-ness' of the object. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.12.12) | |
| A reaction: [Interview with Yann LeCun, Facebook AI director] Fregean philosophers such as Geach think that extracting features is a ridiculous idea, but if even a machine can do it then I suspect that human beings can (and do) manage it too. |
| 16419 | No one has yet devised a rationality test [New Sci.] |
| Full Idea: The financial sector has been clamouring for a rationality test for years. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.10.29) | |
| A reaction: Many aspects of intelligence tests do actually pick out what I would call rationality (which includes 'rational intuition', a new favourite of mine). But they are mixed in with rather mechanical geeky sort of tests. |
| 16417 | About a third of variation in human intelligence is environmental [New Sci.] |
| Full Idea: Possibly a third of the variation in our intelligence is down to the environment in which we grew up - nutrition and education, for example. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.10.29) | |
| A reaction: This presumably leaves the other two-thirds to derive from genetics. I am a big believer in environment. Swapping babies between extremes of cultural environment would hugely affect intelligence, say I. |
| 16418 | People can be highly intelligent, yet very stupid [New Sci.] |
| Full Idea: You really can be highly intelligent, and at the same time very stupid. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.10.29) | |
| A reaction: This is closely related to my observation (from a lifetime of study) that a talent for philosophy has a very limited correlation with standard notions of high intelligence. What matters is how conscious reasoning and intuition relate. Greek 'phronesis'. |
| 18409 | Indexicals apply to singular thought, and mental files have essentially indexical features [Recanati] |
| Full Idea: I defend the applicability of the indexical model to singular thought, and to mental files qua vehicles of singular thought. Mental files, I will argue, possess the essential features of indexicals. | |
| From: François Recanati (Mental Files [2012], 05.1) | |
| A reaction: I love mental files, but am now (thanks to Cappelen and Dever) deeply averse to giving great significance to indexicals. A revised account of files will be needed. |
| 16354 | Indexicality is closely related to singularity, exploiting our direct relations with things [Recanati] |
| Full Idea: Singularity and indexicality are closely related: for indexicals systematically exploit the contextual relations in which we stand to what we talk about. | |
| From: François Recanati (Mental Files [2012], 2.2) | |
| A reaction: Recanati builds a nice case that we may only have an ontology of singular objects because we conceptualise and refer to things in a particular way. He denies the ontology, but that's the bit that interests me. |
| 22247 | Indexicality is not just a feature of language; examples show it also occurs in thought [Recanati] |
| Full Idea: People once took indexicality to be exclusively a property of language, ....but a series of examples seemed to establish that the thought expressed by uttering an indexical sentence is itself indexical (and is thus 'essential'). | |
| From: François Recanati (Mental Files in Flux [2016], 6.1) | |
| A reaction: Perry's example of not realising it is him leaking the sugar in a supermarket is the best known example. Was this a key moment for realising that philosophy of thought is (pace Dummett) more important than philosophy of language? |
| 22248 | How can we communicate indexical thoughts to people not in the right context? [Recanati] |
| Full Idea: Indexical thoughts create an obvious problem with regard to communication. How can we manage to communicate such thoughts to those who are not in the right context? | |
| From: François Recanati (Mental Files in Flux [2016], 7.1) | |
| A reaction: One answer is that you often cannot communicate them. If I write on a wall 'I am here now', that doesn't tell the next passer-by very much. But 'it's raining here' said in a telephone call works fine - if you know the location of the caller. |
| 19484 | Psychologists measure personality along five dimensions [New Sci.] |
| Full Idea: Psychologists have long thought that measuring on a scale of just five personality dimensions - agreeableness, extroversion, neuroticism, conscientiousness and openness to new experiences - can capture all human variations in behaviour and attitude. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.06.13) | |
| A reaction: Researchers are considering a sixth - called 'honesty-humility' - which is roughly how devious people are. The five mentioned here seem to be a well entrenched orthodoxy among professional psychologists. Is personality more superficial than character? |
| 16371 | Files can be confused, if two files correctly have a single name, or one file has two names [Recanati] |
| Full Idea: Paderewski cases are cases in which a subject associates two distinct files with a single name. Inverse Paderewski cases are cases in which there are two names but the subject associates them with a single file. | |
| From: François Recanati (Mental Files [2012], 10.1) | |
| A reaction: In the inverse there are two people with the same name, and someone thinks they are one person (with their combined virtues and vices). E.g. Einstein the famous physicist, and Einstein the famous musicologist. What a man! |
| 16373 | Encylopedic files have further epistemic links, beyond the basic one [Recanati] |
| Full Idea: The reference of a file is the object to which the subject stands in the relevant epistemic relation. In the case of encylopedic entries there is an arbitrary number of distinct relations. The file grows new links in an opportunistic manner. | |
| From: François Recanati (Mental Files [2012], 11.3) | |
| A reaction: I'm not convinced by Recanati's claim that encylopedic files are a distinct type. My files seem to grow these opportunistic links right from their inception. All files seem to have that feature. A file could have four links at its moment of launching. |
| 16375 | Singular thoughts need a mental file, and an acquaintance relation from file to object [Recanati] |
| Full Idea: The mental file framework rests on two principles: that the subject cannot entertain a singular thought about an object without possessing and exercising a mental file about it, and that this requires an acquaintance relation with the object. | |
| From: François Recanati (Mental Files [2012], 12.3) | |
| A reaction: I'm puzzled by the case where I design and build a completely new object. I seem to assemble a file, and only bestow singularity on it towards the end. Or the singularity can just be a placeholder, referred to as 'something'. […see p.158] |
| 16377 | Expected acquaintance can create a thought-vehicle file, but without singular content [Recanati] |
| Full Idea: On my view, actual acquaintance is not necessary to open a mental file; expected acquaintance will suffice; yet opening a mental file itself is not sufficient to entertain a singular thought-content. It only enables a thought-vehicle. | |
| From: François Recanati (Mental Files [2012], 13.1) | |
| A reaction: I'm not clear why I can't create a file with no expectation at all of acquaintance, as in a fictional case. Depends what 'acquaintance' means. Recanati longs for precise distinctions where they may not be available. |
| 16378 | An 'indexed' file marks a file which simulates the mental file of some other person [Recanati] |
| Full Idea: Files function metarepresentationally if they serve to represent how other subjects think about objects in the world. ..An 'indexed' file has an index referring to the other subject whose files the indexed file stands for or simulates. | |
| From: François Recanati (Mental Files [2012], 14.1) | |
| A reaction: Presumably there is an implicit index on all files, which says in a conversation whether my interlocutor does or does not hold the same file-type as me. Recanati wants many 'types' of files, but I suspect there is just one file type. |
| 16387 | Reference by mental files is Millian, in emphasising acquaintance, rather than satisfaction [Recanati] |
| Full Idea: The mental file account preserves the original, Millian inspiration of direct reference theories in giving pride of place to acquaintance relations and downplaying satisfaction factors. | |
| From: François Recanati (Mental Files [2012], 17.3) | |
| A reaction: I find this a very satisfying picture, in which reference links to the simple label of a file (which could be a number), and not to its contents. There are tricky cases of non-existents, fictional entities and purely possible entities to consider. |
| 16361 | A mental file treats all of its contents as concerning one object [Recanati] |
| Full Idea: The role of a mental file is precisely to treat all the information as if it concerned one and the same object, from which it derives. | |
| From: François Recanati (Mental Files [2012], 4.1) | |
| A reaction: Recanati's book focuses entirely on singular objects, but we presumably have files for properties, generalisation, groups etc. Can they only be thought about if they are reified? Maybe. |
| 16358 | The reference of a file is fixed by what it relates to, not the information it contains [Recanati] |
| Full Idea: What files refer to is not determined by properties which the subject takes the referent to have (information, or misinformation, in the file), but through the relations on which the files are based. | |
| From: François Recanati (Mental Files [2012], 3.3) | |
| A reaction: Maybe. 'Lot 22'. I can build up a hypothetical file by saying 'Imagine an animal which is F, G, H…', and build a reference that relates to nothing. Maybe Recanati overestimates the role of his 'epistemically rewarding' relations in file creation. |
| 16367 | There are transient 'demonstrative' files, habitual 'recognitional' files, cumulative 'encyclopedic' files [Recanati] |
| Full Idea: A 'demonstrative' file only exists during the demonstrative relation to something; …a 'recognitional' file is based on 'familiarity' (a disposition to recognise); …an 'encylopedic' file contains all the information on something, however it is gained. | |
| From: François Recanati (Mental Files [2012], 6.1-3) | |
| A reaction: [picked as samples of his taxonomy, pp.70-73] I'm OK with this as long as he doesn't think the categories are sharply separated. I'm inclined to think of files as a single type, drifting in and out of different of modes. |
| 16368 | Files are hierarchical: proto-files, then first-order, then higher-order encyclopedic [Recanati] |
| Full Idea: There is a hierarchy of files. Proto-files are the most basic; conceptual files are generated from them. First-order ones are more basic, as the higher-order encylopedic entries presuppose them. | |
| From: François Recanati (Mental Files [2012], 6.3) | |
| A reaction: This hierarchy might fit into a decent account of categories, if a plausible one could be found. A good prospect for exploring categories would be to start with mental file-types, and work outwards through their relations. |
| 16370 | A file has a 'nucleus' through its relation to the object, and a 'periphery' of links to other files [Recanati] |
| Full Idea: I take a file to have a dual structure, with a 'nucleus' of the file consisting of information derived through the relevant epistemically rewarding relation, while the 'periphery' consists of information derived through linking with other files. | |
| From: François Recanati (Mental Files [2012], 8.3) | |
| A reaction: This sounds strikingly like essentialism to me, though what constitutes the essence is different from the usual explanatory basics. The link, though, is in the causal connection. If we naturally 'essentialise', that will control file-formation. |
| 22242 | Mental files are concepts, which are either collections or (better) containers [Recanati] |
| Full Idea: Mental files are entries in the mental encyclopedia, that is, concepts. Some, following Grice, say they are information collections, but I think of them as containers. Collections are determined by their elements, but containers have independent identity. | |
| From: François Recanati (Mental Files in Flux [2016], Pref) | |
| A reaction: [compressed] [Grice reference is 'Vacuous Names' (1969)] I agree with Recanati. The point is that you can invoke a file by a label, even when you don't know what the content is. |
| 22243 | The Frege case of believing a thing is both F and not-F is explained by separate mental files [Recanati] |
| Full Idea: Frege's Constraint says if a subject believes an object is both F and not-F (as in 'Frege cases'), then the subject thinks of that object under distinct modes of presentation. Having distinct mental files of the object is sufficient to generate this. | |
| From: François Recanati (Mental Files in Flux [2016], Pref) | |
| A reaction: [compressed] When you look at how many semantic puzzles (notably from Frege and Kripke) are solved by the existence of labelled mental files, the case for them is overwhelming. |
| 16381 | The content of thought is what is required to understand it (which involves hearers) [Recanati] |
| Full Idea: As Evans emphasises, what matters when we want to individuate semantic content is what would count as a proper understanding of an utterance; but 'understanding' defines the task of the hearer. | |
| From: François Recanati (Mental Files [2012], 16.2) | |
| A reaction: [cites Evans 1982: 92, 143n, 171] I like to place (following Aristotle) understanding at the centre of all of philosophy, so this seems to me an appealing idea. It makes misunderstandings interesting. |
| 16365 | Mental files are individual concepts (thought constituents) [Recanati] |
| Full Idea: I want mental files (properly speaking) to serve as individual concepts, i.e. thought constituents. | |
| From: François Recanati (Mental Files [2012], 5.3) | |
| A reaction: This is why the concept of mental files is so neat - it gives you a theory of reference and a theory of concepts. I love the files approach because it precisely fits my own introspective experiences. Hope I'm not odd in that way. |
| 16356 | There may be two types of reference in language and thought: descriptive and direct [Recanati] |
| Full Idea: A widely held view, originating with Russell, says there are two types of reference (both in language and thought): descriptive reference, and direct reference. | |
| From: François Recanati (Mental Files [2012], 3.2) | |
| A reaction: I would rather say is there is just one sort of reference, and as many ways of achieving it as you care to come up with. With that view, most of the problems vanish, as far as I can see. People refer. Sentences are nothing but trouble. |
| 16393 | In super-direct reference, the referent serves as its own vehicle of reference [Recanati] |
| Full Idea: In super-direct reference, the sort of thing Russell was after, there is no mode of presentation: the referent itself serves as its own vehicle, as it were. | |
| From: François Recanati (Mental Files [2012], 18.2) | |
| A reaction: To me this is a step too far, because reference is not some physical object like a chair; it is a mental or linguistic phenomenon. Chair's don't refer themselves; it is people who refer. |
| 16386 | Direct reference is strong Millian (just a tag) or weak Kaplanian (allowing descriptions as well) [Recanati] |
| Full Idea: There are two notions of direct reference, the strong Millian notion (where the expression is like a 'tag' with no satisfaction mechanism), and the weaker Kaplanian notion (where reference is compatible with carrying a descriptive meaning). | |
| From: François Recanati (Mental Files [2012], 17.3) | |
| A reaction: I immediately favour the Millian view, which gives a minimal basis for reference, as just a 'peg' (Marcus) to hang things on. I don't take a Millian reference to be the object itself. The concept of a 'tag' or 'label' is key. Mental files have tags. |
| 16372 | Sense determines reference says same sense/same reference; new reference means new sense [Recanati] |
| Full Idea: To say that sense determines reference is to say that the same sense cannot determine distinct referents - any distinction at the level of reference entails a corresponding distinction at the level of sense. | |
| From: François Recanati (Mental Files [2012], 10.2) | |
| A reaction: Does 'the sentry at the gate' change its sense when the guard is changed? Yes. 'The sentry at the gate will stop you'. 'The sentry at the gate is my cousin'. De re/de dicto reference. So changes of de re reference seem to change the sense? |
| 16388 | We need sense as well as reference, but in a non-descriptive form, and mental files do that [Recanati] |
| Full Idea: My view inherits from Frege 'modes of presentation'. Reference is not enough, and sense is needed. …We must make room for non-descriptive modes of presentation, and these are mental files. | |
| From: François Recanati (Mental Files [2012], 18.1) | |
| A reaction: [compressed] Recanati aims to avoid the standard Kripkean criticisms of descriptivism, while being able to handle Frege's puzzles. I take Recanati's mental files theory to be the most promising approach. |
| 16359 | Sense is a mental file (not its contents); similar files for Cicero and Tully are two senses [Recanati] |
| Full Idea: What plays the role of sense is not information in a file, but the file itself. If there are two distinct files, one for 'Cicero' and one for 'Tully', then there are two distinct (non-descriptive) senses, even if the information in both files is the same. | |
| From: François Recanati (Mental Files [2012], 3.4) | |
| A reaction: This may be the best idea in Recanati's book. A sense might be a 'way of coming at the information', rather than some set of descriptions. |
| 16355 | Problems with descriptivism are reference by perception, by communications and by indexicals [Recanati] |
| Full Idea: Three problems with Frege's idea of descriptions in the head are: reference through perception, reference through communicative chains, and reference through indexicals. | |
| From: François Recanati (Mental Files [2012], 3.1) | |
| A reaction: In the end reference has to occur in the head, even if it is social or causal or whatever, so these are not problems that worry me. |
| 16348 | Descriptivism says we mentally relate to objects through their properties [Recanati] |
| Full Idea: Descriptivism is the view that our mental relation to individual objects goes through properties of those objects. …This is so because our knowledge of objects is mediated by our knowledge of their properties. | |
| From: François Recanati (Mental Files [2012], 1.1) | |
| A reaction: The implication is that if you view an object as just a bundle of properties, then you are obliged to hold a descriptive theory of reference. Hence a 'singularist' theory of reference seems to need a primitive notion of an object's identity. |
| 16384 | Definite descriptions reveal either a predicate (attributive use) or the file it belongs in (referential) [Recanati] |
| Full Idea: A definite description may contribute either the singular predicate it encodes (attributive use) or the mental file to what that predicate belongs (referential use). | |
| From: François Recanati (Mental Files [2012], 17.1) | |
| A reaction: This nicely explains Donnellan's distinction in terms of mental files. 'Green' may refer in a shop, but isn't much use in a wood. What to make of 'He's a bit of a Bismark'? |
| 16352 | A rigid definite description can be attributive, not referential: 'the actual F, whoever he is….' [Recanati] |
| Full Idea: A rigid use of a definite description need not be referential: it may be attributive. Thus I may say: 'The actual F, whoever he is, is G'. | |
| From: François Recanati (Mental Files [2012], 2.2) | |
| A reaction: Recanati offers this as a criticism of the attempted 2-D solution to descriptivist accounts of singularity. The singularity is not strong enough, he says. |
| 22245 | A linguistic expression refers to what its associated mental file refers to [Recanati] |
| Full Idea: Mental files determine the reference of linguistic expressions: an expression refers to what the mental file associated with it refers to (at the time of tokening). | |
| From: François Recanati (Mental Files in Flux [2016], 5) | |
| A reaction: Invites the question of how mental files manage to refer, prior to the arrival of a linguistic expression. A mental file is usually fully of descriptions, but it might be no more than a label. |
| 16353 | Singularity cannot be described, and it needs actual world relations [Recanati] |
| Full Idea: As Peirce insisted, singularity as such cannot be described, it can only be given through actual world relations. | |
| From: François Recanati (Mental Files [2012], 2.2) | |
| A reaction: [Peirce - Exact Logic, Papers 3, 1967, §419] This is the key idea for Recanati's case for basing our grasp of singular things on their relation to a mental file. |
| 16382 | Fregean modes of presentation can be understood as mental files [Recanati] |
| Full Idea: A mental file plays the role which Fregean theory assigns to modes of presentation. | |
| From: François Recanati (Mental Files [2012], 17.1) | |
| A reaction: I'm a fan of mental files, and this is a nice pointer to how the useful Fregean insights can be written in a way better grounded in brain operations. Rewriting Frege in neuroscience terms is a nice project for someone. |
| 16389 | If two people think 'I am tired', they think the same thing, and they think different things [Recanati] |
| Full Idea: If you and I think 'I am tired', there is a sense in which we think the same thing, and another sense in which we think different things. | |
| From: François Recanati (Mental Files [2012], 18.1) | |
| A reaction: This is a very nice simple account of the semantic distinctiveness of indexicals, which obviously requires a 'two-tiered framework'. He cites Kaplan and Perry as background. |
| 16363 | Indexicals (like mental files) determine their reference relationally, not by satisfaction [Recanati] |
| Full Idea: The class of indexicals have the same property as mental files, that their reference is determined relationally rather than satisfactionally. | |
| From: François Recanati (Mental Files [2012], 5.1) | |
| A reaction: Recanati is building an account of reference through mental files. This idea may be the clearest point I have yet encountered about indexicals, showing why they are of particular interest to philosophers. |
| 16364 | Indexical don't refer; only their tokens do [Recanati] |
| Full Idea: Indexicals do not refer; only tokens of an indexical refer | |
| From: François Recanati (Mental Files [2012], 5.1) | |
| A reaction: Thus 'Thurs 23rd March 2013' refers, but 'now' doesn't, unless someone produces an utterance of it. This is why indexicals are sometimes called 'token-reflexives'. |
| 16351 | In 2-D semantics, reference is determined, then singularity by the truth of a predication [Recanati] |
| Full Idea: In the two-dimensional framework, what characterises the singular case is the fact that truth-evaluation (of possessing of the reference-fixing property) takes place at a later stage than reference determination. | |
| From: François Recanati (Mental Files [2012], 2.1) | |
| A reaction: This sounds psychologically plausible, which is a big (and unfashionable) plus for me. 1) what are we talking about? 2) what are we saying about it, 3) is it true? |
| 16350 | Two-D semantics is said to help descriptivism of reference deal with singular objects [Recanati] |
| Full Idea: Descriptivism has trouble catching the singularity of objects, construing them as only directly about properties. …To get the truth-conditions right, it is claimed, the descriptivist only as to go two-dimensional. | |
| From: François Recanati (Mental Files [2012], 2.1) | |
| A reaction: I suspect that the descriptivist only has a problem here because context is being ignored. 'That man on the beach' can quickly be made uniquely singular after a brief chat. |
| 16380 | Russellian propositions are better than Fregean thoughts, by being constant through communication [Recanati] |
| Full Idea: The Russellian notion of a proposition is arguably a better candidate for the status of semantic content than the Fregean notion of a thought. For the proposition remains constant from one person to the next. | |
| From: François Recanati (Mental Files [2012], 16.2) | |
| A reaction: A good point, though I rebel against Russellian propositions because they are too much out in the world, and propositions strike me as features of minds. We need to keep propositions separate from facts. |
| 22250 | There are speakers' thoughts and hearers' thoughts, but no further thought attached to the utterance [Recanati] |
| Full Idea: There is the speaker's thought and the thought formed by the hearer. That is all there is. We don't need an additional entity, the thought expressed by the utterance. | |
| From: François Recanati (Mental Files in Flux [2016], 7.2) | |
| A reaction: This fits my view of propositions nicely. They are the two 'thoughts'. The notion of some further abstract 'proposition' with its own mode of independent existence strikes me as ontologically absurd. |
| 22249 | The Naive view of communication is that hearers acquire exactly the thoughts of the speaker [Recanati] |
| Full Idea: The Naive Conception of Communication rests on the idea that communication is the replication of thoughts: the thought the hearer entertains when he understands what the speaker is saying is the very thought which the speaker expressed. | |
| From: François Recanati (Mental Files in Flux [2016], 7.1) | |
| A reaction: It is hard to believe that any modern thinker would believe such a view, given holistic views of language etc. |
| 21167 | Gravity is unusual, in that it always attracts and never repels [New Sci.] |
| Full Idea: Gravity is an odd sort of force, not least because it only ever works one way. Electromagnetism attracts and repels, but with gravity there are only positive masses always attract. | |
| From: New Scientist writers (Why the Universe Exists [2017], 05) | |
| A reaction: This leads to speculation about anti-gravity, but there is no current evidence for it. |
| 19950 | Entropy is the only time-asymmetric law, so time may be linked to entropy [New Sci.] |
| Full Idea: All our physical laws are time-symmetric, ...so things can run forwards or backwards. But entropy is an exception, saying that disorder increases over time. Many physicists therefore suspect that the flow of time is linked to entropy. | |
| From: New Scientist writers (New Scientist articles [2013], 2017.02.04) |
| 21176 | In the Big Bang general relativity fails, because gravity is too powerful [New Sci.] |
| Full Idea: At the origin of the universe gravity becomes so powerful that general relativity breaks down, giving infinity for every answer. | |
| From: New Scientist writers (Why the Universe Exists [2017], 09) |
| 21147 | Quantum electrodynamics incorporates special relativity and quantum mechanics [New Sci.] |
| Full Idea: The theory of electromagnetism that incorporates both special relativity and quantum mechanics is quantum electrodynamics (QED). It was developed by Dirac and others, and perfected in the 1940s. The field is a collection of quanta. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: This builds on Maxwell's earlier classical theory. QED is said to be the best theory in all of physics. |
| 19478 | Light moves at a constant space-time speed, but its direction is in neither space nor time [New Sci.] |
| Full Idea: A light ray always moves at one unit of space per unit of time - a constant diagonal on the graph. ...But the direction that light rays travel in is neither space nor time, and is called 'null'. It is on the edge between space and time. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.06.15) | |
| A reaction: Don't understand this, but it sounds fun. |
| 21155 | Photons have zero rest mass, so virtual photons have infinite range [New Sci.] |
| Full Idea: Photons, the field quanta of the electromagnetic force, have zero rest mass, so virtual photons can exist indefinitely and travel any distance, meaning the electromagnetic force has an infinite range. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) |
| 21161 | In the standard model all the fundamental force fields merge at extremely high energies [New Sci.] |
| Full Idea: The standard model says that the fields of all fundamental forces should merge at extremely high energies, meaning there is also a unified, high-energy field out there. | |
| From: New Scientist writers (Why the Universe Exists [2017], 03) | |
| A reaction: Not quite sure what 'out there' means. This idea is linked to the quest for dark energy. Is this unified phenomenon only found near the Big Bang? |
| 21146 | Electrons move fast, so are subject to special relativity [New Sci.] |
| Full Idea: Electrons in atoms move at high speeds, so they are subject to the special theory of relativity. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: Presumably this implies a frame of reference, and defining velocities relative to other electrons. Plus time-dilation? |
| 19474 | Quantum states are measured by external time, of unknown origin [New Sci.] |
| Full Idea: When we measure the evolution of a quantum state, it is to the beat of an external timepiece of unknown provenance. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.06.15) | |
| A reaction: It is best not to leap to philosophical conclusions when studying modern physics. Evidently time has a very different status in quantum mechanics and in relativity theory. |
| 19473 | The Schrödinger equation describes the evolution of an object's wave function in Hilbert space [New Sci.] |
| Full Idea: A quantum object's state is described by a wave function living in Hilbert space, encompassing all of its possible states. We see how the wave function evolves in time, moving from one state to another, using the Schrödinger equation. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.06.15) | |
| A reaction: [These idea are basic explanations for non-scientific philosophers - please forgive anything that makes you wince] |
| 21148 | The strong force is repulsive at short distances, strong at medium, and fades at long [New Sci.] |
| Full Idea: Experiments show that the nuclear binding force does not follow the inverse square law, but is repulsive at the shortest distances, then attractive, then fades away rapidly as distance increases further. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: So how does it know when to be strong? Magnetism doesn't vary according to distance, and light obeys the inverse square law, because everything is decided at the output. - See 21151 for an explanation. It interacts after departure. |
| 21152 | The strong force binds quarks tight, and the nucleus more weakly [New Sci.] |
| Full Idea: The strong force holds quarks together within protons and neutrons, and residual effects of the strong force bind protons (whch repel one another) and neutrons together in nuclei. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: So the force is much stronger between quarks (which can't escape), and only 'residual' in the nucleus, which must be why smashing nuclei open is fairly easy, but smashin protons open needs higher energies. |
| 21151 | Gluons, the particles carrying the strong force, interact because of their colour charge [New Sci.] |
| Full Idea: In QCD the particles that carry the strong force are called gluons. ...Gluons carry their own colour charges, so they can interact with each other (unlike photons) via the strong nuclear force (which limits the range of the force). | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: So the force varies in strength with distance because the degree of separation among the spreading gluons varies? The force has one range, which is squashed when close, effective at medium, and loses touch with distance? |
| 21150 | Three different colours of quark (as in the proton) can cancel out to give no colour [New Sci.] |
| Full Idea: Just as mixing three colours of light gives white, so the three colour charges of quarks can add up to give no colour. This is what happens in the proton, which always contains one blue-charge quark, one red and one green. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) |
| 21142 | Classifying hadrons revealed two symmetry patterns, produced by three basic elements [New Sci.] |
| Full Idea: Classifying hadrons according to charge, strangeness and spin revealed patterns of eight and ten particles (SU(3) symmetery). The mathematics then showed that these are built from a basic group of only three members. | |
| From: New Scientist writers (Why the Universe Exists [2017], 01) |
| 21143 | Quarks in threes can build hadrons with spin ½ or with spin 3/2 [New Sci.] |
| Full Idea: Quarks in threes can build hadrons with spin ½ (proton, duu; neutron, ddu; lambda, dus), or with spin 3/2 (omega-minus, sss). | |
| From: New Scientist writers (Why the Universe Exists [2017], 01) |
| 21154 | Three particles enable the weak force: W+ and W- are charged, and Z° is not [New Sci.] |
| Full Idea: The quantum field theory of the weak force needs three carrier particles. The W+ and W- are electrically charged, and enable the weak force to change the charge of a particle. The Z° is uncharged, and mediates weak interactions with no charge change. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) |
| 21156 | The weak force particles are heavy, so the force has a short range [New Sci.] |
| Full Idea: The W and Z particles are heavy, and so cannot travel far from their parents. The weak force therefore has a very short range. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) |
| 21145 | The four fundamental forces (gravity, electromagnetism, weak and strong) are the effects of particles [New Sci.] |
| Full Idea: There are four fundamental forces: gravity, electromagnetism, and the weak and strong nuclear forces. Particle physics has so far failed to encompass the force of gravity. The forces that shape our world are themselves the effect of particles. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: Philosophers must take note of the fact that forces are the effects of particles. Common sense pictures forces imposed on particles, like throwing a tennis ball, but the particles are actually the sources of force. The gravitino is speculative. |
| 21153 | The weak force explains beta decay, and the change of type by quarks and leptons [New Sci.] |
| Full Idea: The beta decay of the neutron (into a proton, an electron and an antineutrino) can be described in terms of the weak force, which is 10,000 times weaker than the strong force. It allows the quarks and leptons to change from one type to another. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: This seems to make it the key source of radioactivity. Perhaps it should be called the Force of Change? |
| 21164 | Why do the charges of the very different proton and electron perfectly match up? [New Sci.] |
| Full Idea: Why do the proton and electron charges mirror each other so perfectly when they are such different particles? | |
| From: New Scientist writers (Why the Universe Exists [2017], 04) | |
| A reaction: We seem to have reached a common stage in science, where we have a wonderful descriptive model (the Standard Model), but we cannot explain why what is modelled is the way it is. |
| 21170 | The Standard Model cannot explain dark energy, survival of matter, gravity, or force strength [New Sci.] |
| Full Idea: The standard model cannot explain dark matter, or dark energy (which is causing expansion to accelerate). It cannot explain how matter survived annihilation with anti-matter in the Big Bang, or explain gravity. The strength of each force is unexplained. | |
| From: New Scientist writers (Why the Universe Exists [2017], 06) | |
| A reaction: [compressed] P.141 adds that the model has to be manipulated to keep the Higgs mass low enough. |
| 21158 | Fermions, with spin ½, are antisocial, and cannot share quantum states [New Sci.] |
| Full Idea: Particles with half-integer spin, such as electrons, protons or quarks (all spin ½) have an asymmetry in their wavefunction that makes them antisocial. These particles (Fermions) cannot share a quantum state. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: This is said to explain the complexity of matter, with carbon an especially good example. |
| 21165 | Spin is akin to rotation, and is easily measured in a magnetic field [New Sci.] |
| Full Idea: Spin is a quantum-mechanical property of a particle akin to rotation about its own axis. Particles of different spins respond to magnetic fields in different ways, so it is a relatively easy thing to measure. | |
| From: New Scientist writers (Why the Universe Exists [2017], 04) | |
| A reaction: I wish I knew what 'akin to' meant. Maybe particles are not rigid bodies, so they cannot spin in the way a top can? It must be an electro-magnetic property. Idea 21166 says spin has two possible directions. |
| 21157 | Particles are spread out, with wave-like properties, and higher energy shortens the wavelength [New Sci.] |
| Full Idea: Particles obeying the laws of quantum mechanics have wave-like properties - moving as a quantum wave-function, spread out in space, with wavelengths that get shorter as their energy increases. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: Thus X-rays are dangerous, but long wave radio is not. De Broglie's equation. |
| 21149 | Quarks have red, green or blue colour charge (akin to electric charge) [New Sci.] |
| Full Idea: Quarks have a property akin to electric charge, called their colour charge. It comes in three varieties, red, green and blue. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) |
| 21140 | Spin is a built-in ration of angular momentum [New Sci.] |
| Full Idea: Spin is a built-in ration of angular momentum. | |
| From: New Scientist writers (Why the Universe Exists [2017], 01) | |
| A reaction: As an outsider all I can do is collect descriptions of such properties from the experts. The experts appear to be happy with the numbers inserted in the equations. |
| 21163 | The mass of protons and neutrinos is mostly binding energy, not the quarks [New Sci.] |
| Full Idea: Most of a proton's or neutrino's mass is contained in the interaction energies of a 'sea' of quarks, antiquarks and gluons that bind them. ...You might feel solid, but in fact you're 99 per cent binding energy. | |
| From: New Scientist writers (Why the Universe Exists [2017], 04) | |
| A reaction: This is because energy is equivalent to mass (although gluons are said to have energy but no mass - puzzled by that). This is a fact which needs a bit of time to digest. Once you've grasped we are full of space, you still have understood it. |
| 21168 | Gravitional mass turns out to be the same as inertial mass [New Sci.] |
| Full Idea: There are two types of mass: gravitational mass quantifies how strongly an object feels gravity, while inertial mass quantifies an object's resistance to acceleration. There proven equality is at the heart of General Relativity. | |
| From: New Scientist writers (Why the Universe Exists [2017], 05) | |
| A reaction: It had never occurred to me that these two values might come apart. Doesn't their identical values demonstrate that they are in fact the same thing? Sounds like Hesperus/Phosphorus to me. The book calls it 'mysterious'. |
| 21138 | Neutrons are slightly heavier than protons, and decay into them by emitting an electron [New Sci.] |
| Full Idea: The proton (938.3 MeV) is lighter than the neutron (939.6 MeV) and does not decay, but the heavier neutron can change into a proton by emitting an electron. (If you gather a bucketful of neutrons, after ten minutes only half of them would be left). | |
| From: New Scientist writers (Why the Universe Exists [2017], 01) | |
| A reaction: Protons are more or less eternal, but some theories have them decaying after billions of years. Smashing protons together is a popular pastime for physicists. |
| 21144 | Top, bottom, charm and strange quarks quickly decay into up and down [New Sci.] |
| Full Idea: Quarks can change from one variety to another, and the top, bottom, charm and strange quarks all rapidly decay to the up and down quarks of everyday life. | |
| From: New Scientist writers (Why the Universe Exists [2017], 01) | |
| A reaction: Hence the universe is largely composed of up and down quarks and electrons. The other quarks seem to be more important in the early universe. |
| 21141 | Neutrinos were proposed as the missing energy in neutron beta decay [New Sci.] |
| Full Idea: When a neutron decays into a proton and an electron (one example of beta decay), the energy of the two particles adds up to less than the starting energy of the neutron. Pauli and Fermi concluded that a neutrino (an electron antineutrino) is emitted. | |
| From: New Scientist writers (Why the Universe Exists [2017], 01) | |
| A reaction: I'm wondering how much they could infer about the nature of the new particle (which was only confirmed 26 years later). |
| 21169 | Only neutrinos spin anticlockwise [New Sci.] |
| Full Idea: Neutrinos are the only particles that seem just to spin anticlockwise. | |
| From: New Scientist writers (Why the Universe Exists [2017], 06) | |
| A reaction: See 21166. Anti-neutrino spin is the opposite way. Which way up do you hold the neutrino when pronouncing that it is 'anticlockwise? |
| 21166 | Standard antineutrinos have opposite spin and opposite lepton number [New Sci.] |
| Full Idea: In the conventional standard model neutrinos have antiparticles - which spin in the opposite direction, and have the opposite lepton number. | |
| From: New Scientist writers (Why the Universe Exists [2017], 05) |
| 21171 | The symmetry of unified electromagnetic and weak forces was broken by the Higgs field [New Sci.] |
| Full Idea: In the very early hot universe the electromagnetic and weak nuclear forces were one. The early emergence of the Higgs field led to electroweak symmetry breaking. The W and Z bosons grew fat, and the photon raced away mass-free. | |
| From: New Scientist writers (Why the Universe Exists [2017], 07) |
| 19953 | In string theory space-time has a grainy indivisible substructure [New Sci.] |
| Full Idea: String theory suggests that space-time has a grainy substructure - you can't keep chopping it indefinitely into smaller and smaller pieces. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.11.07) | |
| A reaction: Presumably the proposal is that strings are the true 'atoms'. |
| 21175 | String theory might be tested by colliding strings to make bigger 'stringballs' [New Sci.] |
| Full Idea: A future accelerator might create 'stringballs', when two strings slam into one another and, rather than combining to form a stretched string, make a tangled ball. Finding them would prove string theory. | |
| From: New Scientist writers (Why the Universe Exists [2017], 08) | |
| A reaction: This is the only possible test for string theory which I have seen suggested. How do you 'slam strings together'? |
| 21177 | String theory offers a quantum theory of gravity, by describing the graviton [New Sci.] |
| Full Idea: String theory works as a quantum theory of gravity because string vibrations can describe gravitons, the hypothetical carriers of the gravitational force. | |
| From: New Scientist writers (Why the Universe Exists [2017], 09) | |
| A reaction: Presumably the main aim of a quantum theory of gravity is to include gravitons within particle theory. This idea has to be a main attraction of string theory. Compare Idea 21166. |
| 19476 | String theory needs at least 10 space-time dimensions [New Sci.] |
| Full Idea: String theory needs at least 10 space-time dimensions to be mathematically consistent. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.06.15) | |
| A reaction: Apparently because of 'Ads/CFT', it may be possible to swap this situation for a more tractable 4-dimensional version. |
| 19954 | It is impossible for find a model of actuality among the innumerable models in string theory [New Sci.] |
| Full Idea: String theory has more than 10-to-the-500th solutions, each describing a different sort of universe, so it is nigh-on impossible to find the one solution that corresponds to our geometrically flat, expanding space-time full of particles. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.11.07) |
| 21178 | String theory is now part of 11-dimensional M-Theory, involving p-branes [New Sci.] |
| Full Idea: String theory has now been incorporated into Ed Witten's M-Theory, which is a mathematical framework that lives in 11-dimensional space-time, involving higher-dimensional objects called p-branes, of which strings are a special case. | |
| From: New Scientist writers (Why the Universe Exists [2017], 09) |
| 21179 | Supersymmetric string theory can be expressed using loop quantum gravity [New Sci.] |
| Full Idea: String theory, together with its supersymmetric particles, has recently been rewritten in the space-time described by loop quantum gravity (which says that space-time ust be made from finite chunks). | |
| From: New Scientist writers (Why the Universe Exists [2017], 09) |
| 21162 | Only supersymmetry offers to incorporate gravity into the scheme [New Sci.] |
| Full Idea: Peter Higgs says he is a fan of supersymmetry, largely because it seems to be the only route by which gravity can be brought into the scheme. | |
| From: New Scientist writers (Why the Universe Exists [2017], 03) | |
| A reaction: Peter Higgs proposed the Higgs boson (now discovered). This seems a very good reason to favour supersymmetry. A grand unified theory that left out gravity doesn't seem to be unified quite grandly enough. |
| 21172 | The evidence for supersymmetry keeps failing to appear [New Sci.] |
| Full Idea: The old front-runner theory, supersymmetry, has fallen from grace as the Large Hadron Collider keeps failing to find it. | |
| From: New Scientist writers (Why the Universe Exists [2017], 07) |
| 21173 | Supersymmetry says particles and superpartners were unities, but then split [New Sci.] |
| Full Idea: The key to supersymmetry is that in the high-energy soup of the early universe, particles and their superpartners were indistinguishable. Each pair existed as single massless entities. With expansion and cooling this supersymmetry broke down. | |
| From: New Scientist writers (Why the Universe Exists [2017], 08) |
| 21159 | Supersymmetry has extra heavy bosons and heavy fermions [New Sci.] |
| Full Idea: Supersymmetry posits heavy boson partners for all fermions, and heavy fermions for all bosons. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: The main Fermions are electron, proton and quark. Do extra bosons imply extra forces? Peter Higgs favours supersymmetry. |
| 19947 | Hilbert Space is an abstraction representing all possible states of a quantum system [New Sci.] |
| Full Idea: The elements of the abstract mathematical entity called Hilbert Space represent all the possible states of a quantum system | |
| From: New Scientist writers (New Scientist articles [2013], 1017.02.04) |
| 21160 | The Higgs field means even low energy space is not empty [New Sci.] |
| Full Idea: The point about the Higgs field is that even the lowest-energy state of space is not empty. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: So where is the Higgs field located? Even if there is no utterly empty space, the concept of location implies a concept of space more basic than the fields (about 16, I gather) which occupy it. You can't describe movement without a concept of location. |
| 19955 | Space-time may be a geometrical manifestation of quantum entanglement [New Sci.] |
| Full Idea: A promising theory (based on the 'Maldacena duality' - that string equations for gravity are the same as quantum equations for surface area) is that space-time is really just geometrical manifestations of quantum entanglement. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.11.07) | |
| A reaction: This is a speculation which might unite the incompatible quantum and general relativity theories. |
| 19948 | Einstein's merging of time with space has left us confused about the nature of time [New Sci.] |
| Full Idea: Our hunt for the most basic ingredients of reality has left us muddled about the status of time. One culprit for this was Einstein, whose theory of general relativity merged time with space. | |
| From: New Scientist writers (New Scientist articles [2013], 2017.02.04) |
| 19475 | Relativity makes time and space jointly basic; quantum theory splits them, and prioritises time [New Sci.] |
| Full Idea: Relativity says space and time are on the same footing - together they are the fabric of reality. Quantum mechanics, on the other hand, treats time and space differently, with time occasionally seeming more fundamental. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.06.15) | |
| A reaction: Interesting. When talking about time, people glibly cite relativistic space-time to tell you that time is just another dimension. Now I can reply 'Aaah, but what about time in quantum mechanics? Eh? Eh?'. Excellent. |
| 19949 | Quantum theory relies on a clock outside the system - but where is it located? [New Sci.] |
| Full Idea: After general relativity, quantum mechanics reinstated our familiar notion of time. The buzzing of the quantum world plays out according to the authoritative tick of a clock outside the described system, ...but where is this clock doing its ticking? | |
| From: New Scientist writers (New Scientist articles [2013], 2017.02.04) |
| 19951 | Entropy is puzzling, so we may need to build new laws which include time directionality [New Sci.] |
| Full Idea: Smolin observes that if entropy increases, the early universe must have been highly ordered, which we cannot explain. Maybe we need to build time directionality into the laws, instead of making time depend on entropy. | |
| From: New Scientist writers (New Scientist articles [2013], 2017.02.04) | |
| A reaction: [compressed] |
| 19477 | General relativity predicts black holes, as former massive stars, and as galaxy centres [New Sci.] |
| Full Idea: Black holes are predicted by general relativity, and are thought to exist where massive stars once lived, as well as at the heart of every galaxy. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.06.15) | |
| A reaction: Since black holes now seem to be a certainty, that is one hell of an impressive prediction. |
| 19952 | Black holes have entropy, but general relativity says they are unstructured, and lack entropy [New Sci.] |
| Full Idea: Black holes have a temperature, and hence entropy. ...But if a black hole are just an extreme scrunching of smooth space-time, it should have no substructure, and thus no entropy. This is probably the most obvious incompleteness of general relativity. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.11.07) |
| 16420 | 84.5 percent of the universe is made of dark matter [New Sci.] |
| Full Idea: Dark matter makes up 84.5 percent of the universe's matter. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.10.29) |
| 21174 | Dark matter must have mass, to produce gravity, and no electric charge, to not reflect light [New Sci.] |
| Full Idea: Whatever dark matter is made of, it must have mass to feel and generate gravity; but no electric charge, so it does not interact with light. The leading candidate has been the weakly interacting massive particle (WIMP), much heavier than a proton. | |
| From: New Scientist writers (Why the Universe Exists [2017], 08) | |
| A reaction: Note that it must 'generate' gravity. The idea of a law of gravity which is externally imposed on matter is long dead. Heavy WIMPs have not yet been detected. |
| 17604 | We are halfway to synthesising any molecule we want [New Sci.] |
| Full Idea: Ei-ichi Negishi (Nobel chemist of 2010) says 'the ultimate goal is to be able to synthesise any molecule we want. We are probably about halfway there'. | |
| From: New Scientist writers (New Scientist articles [2013], 2010.10.16) |
| 17603 | Chemistry just needs the periodic table, and protons, electrons and neutrinos [New Sci.] |
| Full Idea: Ei-ichi Negishi (Nobel chemist of 2010) says 'I work with the periodic table in front of me at all times, and approach all challenges in terms of three particles, positively charged protons, negatively charged electrons, and neutral neutrinos'. | |
| From: New Scientist writers (New Scientist articles [2013], 2010.10.16) |
| 1513 | The Egyptians were the first to say the soul is immortal and reincarnated [Herodotus] |
| Full Idea: The Egyptians were the first to claim that the soul of a human being is immortal, and that each time the body dies the soul enters another creature just as it is being born. | |
| From: Herodotus (The Histories [c.435 BCE], 2.123.2) |