42 ideas
| 10170 | While true-in-a-model seems relative, true-in-all-models seems not to be [Reck/Price] |
| Full Idea: While truth can be defined in a relative way, as truth in one particular model, a non-relative notion of truth is implied, as truth in all models. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §4) | |
| A reaction: [The article is actually discussing arithmetic] This idea strikes me as extremely important. True-in-all-models is usually taken to be tautological, but it does seem to give a more universal notion of truth. See semantic truth, Tarski, Davidson etc etc. |
| 10166 | ZFC set theory has only 'pure' sets, without 'urelements' [Reck/Price] |
| Full Idea: In standard ZFC ('Zermelo-Fraenkel with Choice') set theory we deal merely with pure sets, not with additional urelements. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §2) | |
| A reaction: The 'urelements' would the actual objects that are members of the sets, be they physical or abstract. This idea is crucial to understanding philosophy of mathematics, and especially logicism. Must the sets exist, just as the urelements do? |
| 10175 | Three types of variable in second-order logic, for objects, functions, and predicates/sets [Reck/Price] |
| Full Idea: In second-order logic there are three kinds of variables, for objects, for functions, and for predicates or sets. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §5) | |
| A reaction: It is interesting that a predicate seems to be the same as a set, which begs rather a lot of questions. For those who dislike second-order logic, there seems nothing instrinsically wicked in having variables ranging over innumerable multi-order types. |
| 10165 | 'Analysis' is the theory of the real numbers [Reck/Price] |
| Full Idea: 'Analysis' is the theory of the real numbers. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §2) | |
| A reaction: 'Analysis' began with the infinitesimal calculus, which later built on the concept of 'limit'. A continuum of numbers seems to be required to make that work. |
| 10174 | Mereological arithmetic needs infinite objects, and function definitions [Reck/Price] |
| Full Idea: The difficulties for a nominalistic mereological approach to arithmetic is that an infinity of physical objects are needed (space-time points? strokes?), and it must define functions, such as 'successor'. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §4) | |
| A reaction: Many ontologically austere accounts of arithmetic are faced with the problem of infinity. The obvious non-platonist response seems to be a modal or if-then approach. To postulate infinite abstract or physical entities so that we can add 3 and 2 is mad. |
| 10164 | Peano Arithmetic can have three second-order axioms, plus '1' and 'successor' [Reck/Price] |
| Full Idea: A common formulation of Peano Arithmetic uses 2nd-order logic, the constant '1', and a one-place function 's' ('successor'). Three axioms then give '1 is not a successor', 'different numbers have different successors', and induction. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §2) | |
| A reaction: This is 'second-order' Peano Arithmetic, though it is at least as common to formulate in first-order terms (only quantifying over objects, not over properties - as is done here in the induction axiom). I like the use of '1' as basic instead of '0'! |
| 10172 | Set-theory gives a unified and an explicit basis for mathematics [Reck/Price] |
| Full Idea: The merits of basing an account of mathematics on set theory are that it allows for a comprehensive unified treatment of many otherwise separate branches of mathematics, and that all assumption, including existence, are explicit in the axioms. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §4) | |
| A reaction: I am forming the impression that set-theory provides one rather good model (maybe the best available) for mathematics, but that doesn't mean that mathematics is set-theory. The best map of a landscape isn't a landscape. |
| 10167 | Structuralism emerged from abstract algebra, axioms, and set theory and its structures [Reck/Price] |
| Full Idea: Structuralism has emerged from the development of abstract algebra (such as group theory), the creation of axiom systems, the introduction of set theory, and Bourbaki's encyclopaedic survey of set theoretic structures. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §2) | |
| A reaction: In other words, mathematics has gradually risen from one level of abstraction to the next, so that mathematical entities like points and numbers receive less and less attention, with relationships becoming more prominent. |
| 10169 | Relativist Structuralism just stipulates one successful model as its arithmetic [Reck/Price] |
| Full Idea: Relativist Structuralism simply picks one particular model of axiomatised arithmetic (i.e. one particular interpretation that satisfies the axioms), and then stipulates what the elements, functions and quantifiers refer to. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §4) | |
| A reaction: The point is that a successful model can be offered, and it doesn't matter which one, like having any sort of aeroplane, as long as it flies. I don't find this approach congenial, though having a model is good. What is the essence of flight? |
| 10179 | There are 'particular' structures, and 'universal' structures (what the former have in common) [Reck/Price] |
| Full Idea: The term 'structure' has two uses in the literature, what can be called 'particular structures' (which are particular relational systems), but also what can be called 'universal structures' - what particular systems share, or what they instantiate. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §6) | |
| A reaction: This is a very helpful distinction, because it clarifies why (rather to my surprise) some structuralists turn out to be platonists in a new guise. Personal my interest in structuralism has been anti-platonist from the start. |
| 10181 | Pattern Structuralism studies what isomorphic arithmetic models have in common [Reck/Price] |
| Full Idea: According to 'pattern' structuralism, what we study are not the various particular isomorphic models of arithmetic, but something in addition to them: a corresponding pattern. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §7) | |
| A reaction: Put like that, we have to feel a temptation to wield Ockham's Razor. It's bad enough trying to give the structure of all the isomorphic models, without seeking an even more abstract account of underlying patterns. But patterns connect to minds.. |
| 10182 | There are Formalist, Relativist, Universalist and Pattern structuralism [Reck/Price] |
| Full Idea: There are four main variants of structuralism in the philosophy of mathematics - formalist structuralism, relativist structuralism, universalist structuralism (with modal variants), and pattern structuralism. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §9) | |
| A reaction: I'm not sure where Chihara's later book fits into this, though it is at the nominalist end of the spectrum. Shapiro and Resnik do patterns (the latter more loosely); Hellman does modal universalism; Quine does the relativist version. Dedekind? |
| 10168 | Formalist Structuralism says the ontology is vacuous, or formal, or inference relations [Reck/Price] |
| Full Idea: Formalist Structuralism endorses structural methodology in mathematics, but rejects semantic and metaphysical problems as either meaningless, or purely formal, or as inference relations. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §3) | |
| A reaction: [very compressed] I find the third option fairly congenial, certainly in preference to rather platonist accounts of structuralism. One still needs to distinguish the mathematical from the non-mathematical in the inference relations. |
| 10178 | Maybe we should talk of an infinity of 'possible' objects, to avoid arithmetic being vacuous [Reck/Price] |
| Full Idea: It is tempting to take a modal turn, and quantify over all possible objects, because if there are only a finite number of actual objects, then there are no models (of the right sort) for Peano Arithmetic, and arithmetic is vacuously true. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §5) | |
| A reaction: [compressed; Geoffrey Hellman is the chief champion of this view] The article asks whether we are not still left with the puzzle of whether infinitely many objects are possible, instead of existent. |
| 10176 | Universalist Structuralism is based on generalised if-then claims, not one particular model [Reck/Price] |
| Full Idea: Universalist Structuralism is a semantic thesis, that an arithmetical statement asserts a universal if-then statement. We build an if-then statement (using quantifiers) into the structure, and we generalise away from any one particular model. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §5) | |
| A reaction: There remains the question of what is distinctively mathematical about the highly generalised network of inferences that is being described. Presumable the axioms capture that, but why those particular axioms? Russell is cited as an originator. |
| 10177 | Universalist Structuralism eliminates the base element, as a variable, which is then quantified out [Reck/Price] |
| Full Idea: Universalist Structuralism is eliminativist about abstract objects, in a distinctive form. Instead of treating the base element (say '1') as an ambiguous referring expression (the Relativist approach), it is a variable which is quantified out. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §5) | |
| A reaction: I am a temperamental eliminativist on this front (and most others) so this is tempting. I am also in love with the concept of a 'variable', which I take to be utterly fundamental to all conceptual thought, even in animals, and not just a trick of algebra. |
| 10171 | The existence of an infinite set is assumed by Relativist Structuralism [Reck/Price] |
| Full Idea: Relativist Structuralism must first assume the existence of an infinite set, otherwise there would be no model to pick, and arithmetical terms would have no reference. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §4) | |
| A reaction: See Idea 10169 for Relativist Structuralism. They point out that ZFC has an Axiom of Infinity. |
| 15561 | The events that suit semantics may not be the events that suit causation [Lewis] |
| Full Idea: There is no guarantee that events made for semantics are the same as events that are causes and effects. | |
| From: David Lewis (Events [1986], I) | |
| A reaction: This little cri de couer could be a motto for a huge amount of analytic philosophy, which (for some odd reason) thought that mathematics, logic, set theory and formal semantics were good tools for explaining nature. |
| 15565 | Events have inbuilt essences, as necessary conditions for their occurrence [Lewis] |
| Full Idea: Events have their essences built in, in the form of necessary conditions for their occurrence. | |
| From: David Lewis (Events [1986], III) | |
| A reaction: Revealing. He thinks the essence of an event is something which precedes the event. I take it as obvious that if an event has an essence, it will be some features of the event that occur in it and during it. They need to be intrinsic. |
| 15566 | Events are classes, and so there is a mereology of their parts [Lewis] |
| Full Idea: If events are classes, as I propose, then they have a mereology in the way that all classes do: the parts of a class are its subclasses. | |
| From: David Lewis (Events [1986], V) | |
| A reaction: Lewis says events are properties, which he regards as classes. It is not clear that events are strictly mereological. Could one happening be two events? Is WWII a simple sum of its parts? [see p.260] |
| 15567 | Some events involve no change; they must, because causal histories involve unchanges [Lewis] |
| Full Idea: Not all events involve change. We cannot afford to count the unchanges as nonevents, for the unchanges may be needed to complete causal histories. | |
| From: David Lewis (Events [1986], VI) | |
| A reaction: You end up calling non-changes 'events' if you commit to a simplistic theory that all causal histories consist of events. Why not allow conditions as well as events? Lewis concedes that he may be abusing language. |
| 15564 | An event is a property of a unique space-time region [Lewis] |
| Full Idea: I propose to identify an event with a property, or in other words with a class, a unique spatio-temporal region corresponding to where that event occurs. | |
| From: David Lewis (Events [1986], II) | |
| A reaction: [I've run together two separate bits, on p.244 and 245] Lewis cites Montague's similar view, that events are properties of times. |
| 15563 | Properties are very abundant (unlike universals), and are used for semantics and higher-order variables [Lewis] |
| Full Idea: Properties are abundant, numbering at least beth-3 for properties of individuals alone; they are suited to serve as semantic values of arbitrarily complex predicates and gerunds, and higher-order variables. (If there are universals, they are sparse). | |
| From: David Lewis (Events [1986], II n2) | |
| A reaction: To me this is an outrageous hijacking of the notion of property which is needed for explaining the natural world. He seems to be talking about predicates. He wants to leave me with his silly universals - well I don't want them, thank you. |
| 10173 | A nominalist might avoid abstract objects by just appealing to mereological sums [Reck/Price] |
| Full Idea: One way for a nominalist to reject appeal to all abstract objects, including sets, is to only appeal to nominalistically acceptable objects, including mereological sums. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §4) | |
| A reaction: I'm suddenly thinking that this looks very interesting and might be the way to go. The issue seems to be whether mereological sums should be seen as constrained by nature, or whether they are unrestricted. See Mereology in Ontology...|Intrinsic Identity. |
| 3772 | The will, in the beginning, is entirely produced by desire [Mill] |
| Full Idea: The will, in the beginning, is entirely produced by desire. | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.4) | |
| A reaction: This is the sort of simplistic psychology that modern philosophers tend to avoid. Personally I am more Kantian. I will and desire that the answer to 3+2=? is 5, simply because it is true. Mill must realise we can will ourselves to desire something. |
| 3769 | With early training, any absurdity or evil may be given the power of conscience [Mill] |
| Full Idea: There is hardly anything so absurd or so mischievous that it may not, by means of early sanctions and influence, be made to act on the human mind with all the influence of conscience. | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.3) | |
| A reaction: Like this! Think of all the people who have had weird upbringings, and end up feeling guilty about absurd things. Conscience just summarise upbringing and social conventions. |
| 3767 | Motive shows the worth of the agent, but not of the action [Mill] |
| Full Idea: The motive has nothing to do with the morality of the action, though much with the worth of the agent. | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.2) | |
| A reaction: I think it is an error to try to separate these too sharply. Morality can't be purely consequential, because it would make earthquakes immoral. Actions indicate the worth of agents. |
| 3771 | Virtues only have value because they achieve some further end [Mill] |
| Full Idea: Utilitarians believe that actions and dispositions are only virtuous because they promote another end than virtue. | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.4) |
| 3768 | Orthodox morality is the only one which feels obligatory [Mill] |
| Full Idea: The customary morality, that which education and opinion have consecrated, is the only one which presents itself to the mind with the feeling of being in itself obligatory. | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.3) |
| 3776 | Utilitarianism only works if everybody has a totally equal right to happiness [Mill] |
| Full Idea: The Greatest Happiness Principle is a mere form of empty words unless one person's happiness, supposed equal in degree, is counted for exactly as much as another's (Bentham's "everybody to count for one, nobody for more than one"). | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.5) |
| 7202 | The English believe in the task of annihilating evil for the victory of good [Nietzsche on Mill] |
| Full Idea: One continues to believe in good and evil: in such a way that one feels the victory of good and the annihilation of evil to be a task (- this is English; a typical case is that shallow-headed John Stuart Mill). | |
| From: comment on John Stuart Mill (Utilitarianism [1861]) by Friedrich Nietzsche - Writings from Late Notebooks 11[148]e | |
| A reaction: The poor old English try very hard to be clear, sensible, practical and realistic, and get branded as 'shallow' for their pains. Nietzsche was a deeper thinker than Mill, but I would prefer Mill to Heidegger any day. |
| 5935 | Mill's qualities of pleasure is an admission that there are other good states of mind than pleasure [Ross on Mill] |
| Full Idea: Mill's introduction of quality of pleasures into the hedonistic calculus is an unconscious departure from hedonism and a half-hearted admission that there are other qualities than pleasantness in virtue of which states of mind are good. | |
| From: comment on John Stuart Mill (Utilitarianism [1861], Ch.2) by W. David Ross - The Right and the Good §VI | |
| A reaction: Mill argues that experienced people prefer some pleasures to others, but ducks the question of why they might prefer them. It can only be because they have some further desirable quality on top of the equal amount of pleasure. |
| 3764 | Actions are right if they promote pleasure, wrong if they promote pain [Mill] |
| Full Idea: The Greatest Happiness Principle holds that actions are right in proportion as they tend to promote happiness, wrong as they tend to produce the reverse of happiness. By happiness is intended pleasure, and the absence of pain. | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.2) |
| 3763 | Ultimate goods such as pleasure can never be proved to be good [Mill] |
| Full Idea: What can be proved good must be so by being shown to be a means to something admitted to be good without proof. Music is good because it produces pleasure, but what proof is it possible to give that pleasure is good? | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.1) |
| 3765 | Only pleasure and freedom from pain are desirable as ends [Mill] |
| Full Idea: Pleasure and freedom from pain are the only things desirable as ends. | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.2) |
| 3766 | Better to be Socrates dissatisfied than a fool satisfied [Mill] |
| Full Idea: Better to be Socrates dissatisfied than a fool satisfied. | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.2) |
| 3770 | General happiness is only desirable because individuals desire their own happiness [Mill] |
| Full Idea: No reason can be given why the general happiness is desirable, except that each person, so far as he believes it to be attainable, desires his own happiness. | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.4) |
| 6697 | Moral rules protecting human welfare are more vital than local maxims [Mill] |
| Full Idea: Moral rules which forbid mankind to hurt one another are more vital to human well-being than any maxims about some department of human affairs; ..though in particular cases a social duty is so important, as to overrule any general maxim of justice. | |
| From: John Stuart Mill (Utilitarianism [1861]), quoted by Gordon Graham - Eight Theories of Ethics Ch.7 | |
| A reaction: The qualification is realistic, but raises the question of whether an 'act' calculation will always overrule any 'rule'. Maybe rule utilitirianism is just act utilitarianism, but ensuring that the calculations are long-term and extensive. (1871 edn) |
| 3774 | Rights are a matter of justice, not of benevolence [Mill] |
| Full Idea: Wherever there is a right, the case is one of justice, and not of the virtue of benevolence. | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.5) |
| 3773 | No individual has the right to receive our benevolence [Mill] |
| Full Idea: No one has a moral right to our generosity or beneficence, because we are not morally bound to practise those virtues towards any given individual. | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.5) |
| 3775 | A right is a valid claim to society's protection [Mill] |
| Full Idea: When we call anything a person's right, we mean that he has a valid claim on society to protect him in the possession of it. | |
| From: John Stuart Mill (Utilitarianism [1861], Ch.5) |
| 15562 | Causation is a general relation derived from instances of causal dependence [Lewis] |
| Full Idea: Causation is the ancestral of causal dependence: event c causes event e iff either e depends on c, or e depends on an intermediate event which in turn depends on c, or.... | |
| From: David Lewis (Events [1986], I) | |
| A reaction: This is Lewis making sure that we don't postulate some huge bogus thing called 'Causation' which is supposed to be in charge of Nature. Good point. |