37 ideas
| 23027 | Ideals and metaphysics are practical, not imaginative or speculative [Green,TH, by Muirhead] |
| Full Idea: To T.H. Green an ideal was no creation of an idle imagination, metaphysics no mere play of the speculative reason. Ideals were the most solid, and metaphysics the most practical thing about a man. | |
| From: report of T.H. Green (works [1875]) by John H. Muirhead - The Service of the State I | |
| A reaction: This is despite the fact that Green was an idealist in the Hegelian tradition. I like this. I see it not just as ideals having practical guiding influence, but also that ideals themselves arising out of experience. |
| 23030 | Truth is a relation to a whole of organised knowledge in the collection of rational minds [Green,TH, by Muirhead] |
| Full Idea: When we speak of anything as true or false, we do so on the ground of its relation to a whole of organised knowledge existing actually in no human mind, but prefigured in every mind which is possessed of reason. | |
| From: report of T.H. Green (works [1875]) by John H. Muirhead - The Service of the State I n1 | |
| A reaction: This seems to be the super-idealist view of the coherence account of truth. I have no idea what 'prefigured' means here. |
| 8729 | Intuitionists deny excluded middle, because it is committed to transcendent truth or objects [Shapiro] |
| Full Idea: Intuitionists in mathematics deny excluded middle, because it is symptomatic of faith in the transcendent existence of mathematical objects and/or the truth of mathematical statements. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 1.2) | |
| A reaction: There are other problems with excluded middle, such as vagueness, but on the whole I, as a card-carrying 'realist', am committed to the law of excluded middle. |
| 8763 | The number 3 is presumably identical as a natural, an integer, a rational, a real, and complex [Shapiro] |
| Full Idea: It is surely wise to identify the positions in the natural numbers structure with their counterparts in the integer, rational, real and complex number structures. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 10.2) | |
| A reaction: The point is that this might be denied, since 3, 3/1, 3.00.., and -3*i^2 are all arrived at by different methods of construction. Natural 3 has a predecessor, but real 3 doesn't. I agree, intuitively, with Shapiro. Russell (1919) disagreed. |
| 18249 | Cauchy gave a formal definition of a converging sequence. [Shapiro] |
| Full Idea: A sequence a1,a2,... of rational numbers is 'Cauchy' if for each rational number ε>0 there is a natural number N such that for all natural numbers m, n, if m>N and n>N then -ε < am - an < ε. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 7.2 n4) | |
| A reaction: The sequence is 'Cauchy' if N exists. |
| 8764 | Categories are the best foundation for mathematics [Shapiro] |
| Full Idea: There is a dedicated contingent who hold that the category of 'categories' is the proper foundation for mathematics. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 10.3 n7) | |
| A reaction: He cites Lawvere (1966) and McLarty (1993), the latter presenting the view as a form of structuralism. I would say that the concept of a category will need further explication, and probably reduce to either sets or relations or properties. |
| 8762 | Two definitions of 3 in terms of sets disagree over whether 1 is a member of 3 [Shapiro] |
| Full Idea: Zermelo said that for each number n, its successor is the singleton of n, so 3 is {{{null}}}, and 1 is not a member of 3. Von Neumann said each number n is the set of numbers less than n, so 3 is {null,{null},{null,{null}}}, and 1 is a member of 3. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 10.2) | |
| A reaction: See Idea 645 - Zermelo could save Plato from the criticisms of Aristotle! These two accounts are cited by opponents of the set-theoretical account of numbers, because it seems impossible to arbitrate between them. |
| 8760 | Numbers do not exist independently; the essence of a number is its relations to other numbers [Shapiro] |
| Full Idea: The structuralist vigorously rejects any sort of ontological independence among the natural numbers; the essence of a natural number is its relations to other natural numbers. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 10.1) | |
| A reaction: This seems to place the emphasis on ordinals (what order?) rather than on cardinality (how many?). I am strongly inclined to think that this is the correct view, though you can't really have relations if there is nothing to relate. |
| 8761 | A 'system' is related objects; a 'pattern' or 'structure' abstracts the pure relations from them [Shapiro] |
| Full Idea: A 'system' is a collection of objects with certain relations among them; a 'pattern' or 'structure' is the abstract form of a system, highlighting the interrelationships and ignoring any features they do not affect how they relate to other objects. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 10.1) | |
| A reaction: Note that 'ignoring' features is a psychological account of abstraction, which (thanks to Frege and Geach) is supposed to be taboo - but which I suspect is actually indispensable in any proper account of thought and concepts. |
| 8744 | Logicism seems to be a non-starter if (as is widely held) logic has no ontology of its own [Shapiro] |
| Full Idea: The thesis that principles of arithmetic are derivable from the laws of logic runs against a now common view that logic itself has no ontology. There are no particular logical objects. From this perspective logicism is a non-starter. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 5.1) | |
| A reaction: This criticism strikes me as utterly devastating. There are two routes to go: prove that logic does have an ontology of objects (what would they be?), or - better - deny that arithmetic contains any 'objects'. Or give up logicism. |
| 8749 | Term Formalism says mathematics is just about symbols - but real numbers have no names [Shapiro] |
| Full Idea: Term Formalism is the view that mathematics is just about characters or symbols - the systems of numerals and other linguistic forms. ...This will cover integers and rational numbers, but what are real numbers supposed to be, if they lack names? | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 6.1.1) | |
| A reaction: Real numbers (such as pi and root-2) have infinite decimal expansions, so we can start naming those. We could also start giving names like 'Harry' to other reals, though it might take a while. OK, I give up. |
| 8750 | Game Formalism is just a matter of rules, like chess - but then why is it useful in science? [Shapiro] |
| Full Idea: Game Formalism likens mathematics to chess, where the 'content' of mathematics is exhausted by the rules of operating with its language. ...This, however, leaves the problem of why the mathematical games are so useful to the sciences. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 6.1.2) | |
| A reaction: This thought pushes us towards structuralism. It could still be a game, but one we learned from observing nature, which plays its own games. Chess is, after all, modelled on warfare. |
| 8752 | Deductivism says mathematics is logical consequences of uninterpreted axioms [Shapiro] |
| Full Idea: The Deductivist version of formalism (sometimes called 'if-thenism') says that the practice of mathematics consists of determining logical consequences of otherwise uninterpreted axioms. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 6.2) | |
| A reaction: [Hilbert is the source] More plausible than Term or Game Formalism (qv). It still leaves the question of why it seems applicable to nature, and why those particular axioms might be chosen. In some sense, though, it is obviously right. |
| 8753 | Critics resent the way intuitionism cripples mathematics, but it allows new important distinctions [Shapiro] |
| Full Idea: Critics commonly complain that the intuitionist restrictions cripple the mathematician. On the other hand, intuitionist mathematics allows for many potentially important distinctions not available in classical mathematics, and is often more subtle. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 7.1) | |
| A reaction: The main way in which it cripples is its restriction on talk of infinity ('Cantor's heaven'), which was resented by Hilbert. Since high-level infinities are interesting, it would be odd if we were not allowed to discuss them. |
| 8731 | Conceptualist are just realists or idealist or nominalists, depending on their view of concepts [Shapiro] |
| Full Idea: I classify conceptualists according to what they say about properties or concepts. If someone classified properties as existing independent of language I would classify her as a realist in ontology of mathematics. Or they may be idealists or nominalists. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 2.2.1) | |
| A reaction: In other words, Shapiro wants to eliminate 'conceptualist' as a useful label in philosophy of mathematics. He's probably right. All thought involves concepts, but that doesn't produce a conceptualist theory of, say, football. |
| 8730 | 'Impredicative' definitions refer to the thing being described [Shapiro] |
| Full Idea: A definition of a mathematical entity is 'impredicative' if it refers to a collection that contains the defined entity. The definition of 'least upper bound' is impredicative as it refers to upper bounds and characterizes a member of this set. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 1.2) | |
| A reaction: The big question is whether mathematics can live with impredicative definitions, or whether they threaten to be viciously circular, and undermine the whole enterprise. |
| 23044 | All knowledge rests on a fundamental unity between the knower and what is known [Green,TH, by Muirhead] |
| Full Idea: All knowledge is seen on ultimate analysis to rest upon the idea of a fundamental unity between subject and object, between the knower and that which there is to be known. | |
| From: report of T.H. Green (works [1875]) by John H. Muirhead - The Service of the State III | |
| A reaction: I don't really understand this thought, but I think it embodies the essence of Hegelian idealism. If I know a tree in the wood, any 'unity' between us strikes as merely imaginary. If the tree isn't separate, what does 'knowing' it mean? |
| 8725 | Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro] |
| Full Idea: Rationalism is a long-standing school that can be characterized as an attempt to extend the perceived methodology of mathematics to all of knowledge. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 1.1) | |
| A reaction: Sometimes called 'Descartes's Dream', or the 'Enlightenment Project', the dream of proving everything. Within maths, Hilbert's Programme aimed for the same certainty. Idea 22 is the motto for the opposition to this approach. |
| 23034 | The ultimate test for truth is the systematic interdependence in nature [Green,TH, by Muirhead] |
| Full Idea: Systematic interdependence in the world of nature is the ultimate test of truth. | |
| From: report of T.H. Green (works [1875]) by John H. Muirhead - The Service of the State II | |
| A reaction: Green (or Muirhead) drifts between coherence as the nature of truth and coherence as the nature of justification. He it is the 'test' for truth, which was Russell's view. |
| 23032 | What is distinctive of human life is the desire for self-improvement [Green,TH, by Muirhead] |
| Full Idea: All that is distinctively human in the life of man springs not from the desire to possess this or that object, and so far to realise a better, but to be something more and better than he is. | |
| From: report of T.H. Green (works [1875]) by John H. Muirhead - The Service of the State II | |
| A reaction: An example of Victorian optimism, I think. I'm guessing that people who are not motivated by this impulse are not behaving in a way that is 'distinctively human'. That said, this is an interesting aspect of human nature. |
| 23033 | Hedonism offers no satisfaction, because what we desire is self-betterment [Green,TH, by Muirhead] |
| Full Idea: Hedonism failed because it offered as an end of human aspiration an object in which the human spirit, pledged by its own nature to self-betterment, …could never find satisfaction. | |
| From: report of T.H. Green (works [1875]) by John H. Muirhead - The Service of the State II | |
| A reaction: It is always both sad and amusing to see that 150 years ago someone wrote of a doctrine that is still with us that it has 'failed'. Nowadays they try to say the same of physicalism. His objection rests on optimism about humanity. |
| 7127 | If men are good you should keep promises, but they aren't, so you needn't [Machiavelli] |
| Full Idea: If all men were good, promising-breaking would not be good, but because they are bad and do not keep their promises to you, you likewise do not have to keep yours to them. | |
| From: Niccolo Machiavelli (The Prince [1513], Ch.18) | |
| A reaction: A rather depressing proposal to get your promise-breaking in first, based on the pessimistic view that people cannot be improved. The subsequent history of ethics in Europe showed Machiavelli to be wrong. Gentlemen began to keep their word. |
| 23045 | Politics is compromises, which seem supported by a social contract, but express the will of no one [Green,TH] |
| Full Idea: Where laws and institutions are apparently the work of deliberate volition, they are in reality the result of a compromise, which while by a kind of social contract it has the acquiescence of all, expresses the will of none. | |
| From: T.H. Green (works [1875]), quoted by John H. Muirhead - The Service of the State III | |
| A reaction: Politicians who claim to be enacting the 'will of the people' (e.g. when they won a referendum 52-48) are simply lying. Committees usually end up enacting one person's will, but often without realising what has happened. |
| 6309 | The principle foundations of all states are good laws and good armies [Machiavelli] |
| Full Idea: The principle foundations of all states are good laws and good armies. | |
| From: Niccolo Machiavelli (The Prince [1513], Ch.11) | |
| A reaction: We may be wondering, since 1945, whether a good army is any longer essential, but it would be a foolish modern state which didn't at least form a strong alliance with a state which had a strong army. Fertile land is a huge benefit to a state. |
| 23050 | The ideal is a society in which all citizens are ladies and gentlemen [Green,TH] |
| Full Idea: With all seriousness and reverence we may hope and pray for a condition of English society in which all honest citizens will recognise themselves and be recognised by each other as gentlemen. | |
| From: T.H. Green (works [1875]), quoted by John H. Muirhead - The Service of the State IV | |
| A reaction: Call me old fashioned but, as long as we expand this to include ladies, I like this thought. Chaucer's knight (in his Prologue) should be our national role model. The true gentleman is an Aristotelian ideal. |
| 23052 | Enfranchisement is an end in itself; it makes a person moral, and gives a basis for respect [Green,TH] |
| Full Idea: Enfranchisement of the people is an end in itself. …Only citizenship makes the moral man; only citizenship gives that respect which is the true basis of the respect for others. | |
| From: T.H. Green (works [1875], iii:436), quoted by John H. Muirhead - The Service of the State IV | |
| A reaction: Should people respect their betters? If so, that is a sort of deferential respect which is different from the mutual respect between equals. That said, I wholly approve of this idea. |
| 6305 | To retain a conquered state, wipe out the ruling family, and preserve everything else [Machiavelli] |
| Full Idea: If a ruler acquires a state and is determined to keep it, he observes two cautions: he wipes out the family of their long-established princes; and he does not change either their laws or their taxes; in a short time they will unite with his old princedom. | |
| From: Niccolo Machiavelli (The Prince [1513], Ch.3) | |
| A reaction: This nicely illustrates the firmness of purpose for which Machiavelli has become a byword. The question is whether Machiavelli had enough empirical evidence to support this induction. The British in India seem to have been successful without it. |
| 6306 | People are vengeful, so be generous to them, or destroy them [Machiavelli] |
| Full Idea: Men should be either treated generously or destroyed, because they take revenge for slight injuries. | |
| From: Niccolo Machiavelli (The Prince [1513], Ch.3) | |
| A reaction: This sounds like good advice, and works quite well in school teaching too. It seems like advice drawn from the growth of the Roman Empire, rather than from dealing with sophisticated and educated people. |
| 6308 | A sensible conqueror does all his harmful deeds immediately, because people soon forget [Machiavelli] |
| Full Idea: A prudent conqueror makes a list of all the harmful deeds he must do, and does them all at once, so that he need not repeat them every day, which then makes men feel secure, and gains their support by treating them well. | |
| From: Niccolo Machiavelli (The Prince [1513], Ch.8) | |
| A reaction: This might work for a new government in a democracy, or a new boss in a business. It sounds horribly true; dreadful deeds done a long time ago can be completely forgotten, as when reformed criminals become celebrities. |
| 23036 | The good is identified by the capacities of its participants [Green,TH, by Muirhead] |
| Full Idea: The modern idea of the good has developed in respect of the range of persons who have the capacity and therefore the right to participate in this good. | |
| From: report of T.H. Green (works [1875]) by John H. Muirhead - The Service of the State II | |
| A reaction: Green is a notable Victorian liberal, starting from an idealist metaphysics. This is an intriguing view of liberal values. The concept of the good should be what suits persons with full capacity. Having the capacity bestows the right of access to it. Hm. |
| 23039 | A true state is only unified and stabilised by acknowledging individuality [Green,TH, by Muirhead] |
| Full Idea: In so far as society commits itself to the principle of individuality of its citizens does it realise the unity and stability that constitute it a true 'State'. | |
| From: report of T.H. Green (works [1875]) by John H. Muirhead - The Service of the State II | |
| A reaction: This asserts the liberal vision of a state, rather than asserting a fact. A state consistently mostly of slaves still seems to be a state, and may achieve a lot. |
| 23038 | People only develop their personality through co-operation with the social whole [Green,TH, by Muirhead] |
| Full Idea: In so far as the individual commits himself to the principle of co-operation in a social whole does he realise his end as individual personality. | |
| From: report of T.H. Green (works [1875]) by John H. Muirhead - The Service of the State II | |
| A reaction: This makes for a very communitarian type of liberalism. The question is whether we create insitutions which suck our free citizens into a communal way of life, or whether that is a matter of their own initiative. |
| 6307 | A desire to conquer, and men who do it, are always praised, or not blamed [Machiavelli] |
| Full Idea: It is very natural and normal to wish to conquer, and when men do it who can, they always will be praised, or not blamed. | |
| From: Niccolo Machiavelli (The Prince [1513], Ch.3) | |
| A reaction: This view seems shocking to us, but it seems to me that this was a widely held view up until the time of Nietzsche, but came to a swift end with the invention of the machine gun in about 1885, followed by the heavy bomber and atomic bomb. |
| 7486 | Machiavelli emancipated politics from religion [Machiavelli, by Watson] |
| Full Idea: Machiavelli emancipated politics from religion. | |
| From: report of Niccolo Machiavelli (The Prince [1513]) by Peter Watson - Ideas Ch.24 | |
| A reaction: Interestingly, he seems to have done it by saying that ideals are irrelevant to politics, but gradually secular ideals crept back in (sometimes disastrously). A balance needs to be struck on idealism. |
| 23040 | If something develops, its true nature is embodied in its end [Green,TH] |
| Full Idea: To anyone who understands a process of development, the result being developed is the reality; and it is its ability to become this that the subject undergoing development has its true nature. | |
| From: T.H. Green (works [1875], iii: 224), quoted by John H. Muirhead - The Service of the State II | |
| A reaction: Although this contains the dubious Hegelian idea that development tends towards some 'end', presented as fixed and final, it still seems important that anything accepted as a 'development' is the expression of some natural potential. |
| 23031 | God is the ideal end of the mature mind's final development [Green,TH] |
| Full Idea: God is a subject which is eternally all that the self-conscious subject as developed in time has the possibility of becoming. | |
| From: T.H. Green (works [1875]), quoted by John H. Muirhead - The Service of the State I | |
| A reaction: [Ethics p.197] Reminiscent of Peirce's account of truth, as the ideal end of enquiry. If God is a human ideal, we either limit God, or exaggerate our powers of idealisation. |
| 23041 | God is the realisation of the possibilities of each man's self [Green,TH] |
| Full Idea: God is identical with the self of every man in the sense of being the realisation of its determinate possibilities.…In being conscious of himself man is conscious of God and thus knows that God is, but only in so far as he knows what he himself really is. | |
| From: T.H. Green (works [1875], iii:226-7), quoted by John H. Muirhead - The Service of the State II | |
| A reaction: Does this, by the transitivity of identity, imply the identity of all individual men? Do we all contain identical possibilities, which converge on a unified concept of God? I always take the monotheistic God to far exceed mere human possibilities. |