42 ideas
15390 | Metaphysics attempts to give an account of everything, in terms of categories and principles [Simons] |
Full Idea: Metaphysics, the noblest of philosophic enterprises, is an attempt to give an account of everything. ...Its job is to provide a universal framework (of categories and principles) within which anything whatever can take its place. | |
From: Peter Simons (Whitehead: process and cosmology [2009], 'Speculative') | |
A reaction: Bravo! I take metaphysics to be entirely continuous with science, but operating entirely at the highest level of generality. See Westerhoff on categories, though. The enterprise may not be going too well. |
10775 | The axiom of choice now seems acceptable and obvious (if it is meaningful) [Tharp] |
Full Idea: The main objection to the axiom of choice was that it had to be given by some law or definition, but since sets are arbitrary this seems irrelevant. Formalists consider it meaningless, but set-theorists consider it as true, and practically obvious. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §3) |
10766 | Logic is either for demonstration, or for characterizing structures [Tharp] |
Full Idea: One can distinguish at least two quite different senses of logic: as an instrument of demonstration, and perhaps as an instrument for the characterization of structures. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) | |
A reaction: This is trying to capture the proof-theory and semantic aspects, but merely 'characterizing' something sounds like a rather feeble aspiration for the semantic side of things. Isn't it to do with truth, rather than just rule-following? |
10767 | Elementary logic is complete, but cannot capture mathematics [Tharp] |
Full Idea: Elementary logic cannot characterize the usual mathematical structures, but seems to be distinguished by its completeness. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
10769 | Second-order logic isn't provable, but will express set-theory and classic problems [Tharp] |
Full Idea: The expressive power of second-order logic is too great to admit a proof procedure, but is adequate to express set-theoretical statements, and open questions such as the continuum hypothesis or the existence of big cardinals are easily stated. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
10762 | In sentential logic there is a simple proof that all truth functions can be reduced to 'not' and 'and' [Tharp] |
Full Idea: In sentential logic there is a simple proof that all truth functions, of any number of arguments, are definable from (say) 'not' and 'and'. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §0) | |
A reaction: The point of 'say' is that it can be got down to two connectives, and these are just the usual preferred pair. |
10776 | The main quantifiers extend 'and' and 'or' to infinite domains [Tharp] |
Full Idea: The symbols ∀ and ∃ may, to start with, be regarded as extrapolations of the truth functional connectives ∧ ('and') and ∨ ('or') to infinite domains. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §5) |
10774 | There are at least five unorthodox quantifiers that could be used [Tharp] |
Full Idea: One might add to one's logic an 'uncountable quantifier', or a 'Chang quantifier', or a 'two-argument quantifier', or 'Shelah's quantifier', or 'branching quantifiers'. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §3) | |
A reaction: [compressed - just listed for reference, if you collect quantifiers, like collecting butterflies] |
10773 | The Löwenheim-Skolem property is a limitation (e.g. can't say there are uncountably many reals) [Tharp] |
Full Idea: The Löwenheim-Skolem property seems to be undesirable, in that it states a limitation concerning the distinctions the logic is capable of making, such as saying there are uncountably many reals ('Skolem's Paradox'). | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
10777 | Skolem mistakenly inferred that Cantor's conceptions were illusory [Tharp] |
Full Idea: Skolem deduced from the Löwenheim-Skolem theorem that 'the absolutist conceptions of Cantor's theory' are 'illusory'. I think it is clear that this conclusion would not follow even if elementary logic were in some sense the true logic, as Skolem assumed. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §7) | |
A reaction: [Tharp cites Skolem 1962 p.47] Kit Fine refers to accepters of this scepticism about the arithmetic of infinities as 'Skolemites'. |
10765 | Soundness would seem to be an essential requirement of a proof procedure [Tharp] |
Full Idea: Soundness would seem to be an essential requirement of a proof procedure, since there is little point in proving formulas which may turn out to be false under some interpretation. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
10763 | Completeness and compactness together give axiomatizability [Tharp] |
Full Idea: Putting completeness and compactness together, one has axiomatizability. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §1) |
10770 | If completeness fails there is no algorithm to list the valid formulas [Tharp] |
Full Idea: In general, if completeness fails there is no algorithm to list the valid formulas. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) | |
A reaction: I.e. the theory is not effectively enumerable. |
10771 | Compactness is important for major theories which have infinitely many axioms [Tharp] |
Full Idea: It is strange that compactness is often ignored in discussions of philosophy of logic, since the most important theories have infinitely many axioms. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) | |
A reaction: An example of infinite axioms is the induction schema in first-order Peano Arithmetic. |
10772 | Compactness blocks infinite expansion, and admits non-standard models [Tharp] |
Full Idea: The compactness condition seems to state some weakness of the logic (as if it were futile to add infinitely many hypotheses). To look at it another way, formalizations of (say) arithmetic will admit of non-standard models. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
10764 | A complete logic has an effective enumeration of the valid formulas [Tharp] |
Full Idea: A complete logic has an effective enumeration of the valid formulas. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
10768 | Effective enumeration might be proved but not specified, so it won't guarantee knowledge [Tharp] |
Full Idea: Despite completeness, the mere existence of an effective enumeration of the valid formulas will not, by itself, provide knowledge. For example, one might be able to prove that there is an effective enumeration, without being able to specify one. | |
From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) | |
A reaction: The point is that completeness is supposed to ensure knowledge (of what is valid but unprovable), and completeness entails effective enumerability, but more than the latter is needed to do the key job. |
7222 | It is a crime for someone with a violent disposition to get drunk [Mill] |
Full Idea: The making himself drunk, in a person whom drunkenness excites to do harm to others, is a crime against others. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: This principle (based on knowing your own dispositions) is a very good account of the ethics drunkenness. We have a moral duty to know and remember our own dispositions. Violent people should avoid arguments as well as alcohol. |
7214 | Ethics rests on utility, which is the permanent progressive interests of people [Mill] |
Full Idea: I regard utility as the ultimate appeal on all ethical questions; but it must be utility in the largest sense, grounded on the permanent interests of a man as a progressive being. | |
From: John Stuart Mill (On Liberty [1857], Ch.1) | |
A reaction: Mill, writing in praise of personal liberty, is desperate to introduce a paternalistic element into his politics, and the 'maximisation of happiness' will justify such paternalism, while his basic liberal principle (Idea 7211) won't. Mill's Dilemma. |
7212 | Individuals have sovereignty over their own bodies and minds [Mill] |
Full Idea: Over himself, over his own body and mind, the individual is sovereign. | |
From: John Stuart Mill (On Liberty [1857], Ch.1) | |
A reaction: If I should not even think about evil deeds, then neither should you. I would prevent you if I could. I would prevent you from drinking yourself to death, if I could. It is just that intrusions into private lives leads to greater trouble. |
7210 | The will of the people is that of the largest or most active part of the people [Mill] |
Full Idea: The will of the people practically means the will of the most numerous or the most active part of the people. | |
From: John Stuart Mill (On Liberty [1857], Ch.1) | |
A reaction: Hence the nicely coined modern phrase 'the silent majority', on whose behalf certain politicians, usually conservative, offer to speak. It is unlikely that the silent majority are actually deeply opposed to the views of the very active part. |
7227 | It is evil to give a government any more power than is necessary [Mill] |
Full Idea: Government interference should be restricted because of the great evil of adding unnecessarily to its power. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: This would need justification, because it might be replied that individuals should not have unnecessary power either. The main problem is that governments have armies, police and money. |
7228 | Individuals often do things better than governments [Mill] |
Full Idea: Government power should be restricted because things are often done better by individuals. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: This contains some truth, but it is obvious that innumerable things can be done better by governments, and also (and more importantly) that innumerable other good things might be done by governments which individuals can't be bothered to do. |
7230 | Aim for the maximum dissemination of power consistent with efficiency [Mill] |
Full Idea: The safest practical ideal is to aim for the greatest dissemination of power consistent with efficiency. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: This is a very nice principle, which I would think desirable within an institution as well as on the scale of the state. I am becoming a fan of Mill's politics. I still say that freedom is an overrated virtue, so efficiency must be underrated. |
20515 | Maximise happiness by an area of strict privacy, and an area of utilitarian interventions [Mill, by Wolff,J] |
Full Idea: For Mill the greatest happiness will be achieved by giving people a private sphere of interests where no intervention is permitted, while allowing a public sphere where intervention is possible, but only on utilitarian grounds. | |
From: report of John Stuart Mill (On Liberty [1857]) by Jonathan Wolff - An Introduction to Political Philosophy (Rev) 4 'Liberty' | |
A reaction: This is probably standard liberal practice nowadays. Freely consenting adult sexual activity is agreed to be wholly private. At least some lip-service is paid to increasing happiness when government intervenes. |
7229 | People who transact their own business will also have the initiative to control their government [Mill] |
Full Idea: A people accustomed to transacting their own business is certain to be free; it will never let itself be enslaved by any man or body of men because these are able to seize and pull the reins of the central administration. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: He makes reference to Americans. This is an important idea, because it shows that democratic control is not just a matter of elections (which can be abolished or suborned), but is also a characteristic of a certain way of life. |
7211 | Prevention of harm to others is the only justification for exercising power over people [Mill] |
Full Idea: The only purpose for which power can be rightfully exercised over any member of a civilised community, against his will, is to prevent harm to others; his own good, either physical or moral, is not a sufficient warrant. | |
From: John Stuart Mill (On Liberty [1857], Ch.1) | |
A reaction: This is the key idea in Mill's liberalism, though he goes on to offer some qualifications of this absolute prohibition. I don't disagree with this principle, but there may be a lot more indirect harm than we realise (eg. in allowing liberal sex or drugs). |
7231 | The worth of a State, in the long run, is the worth of the individuals composing it [Mill] |
Full Idea: The worth of a State, in the long run, is the worth of the individuals composing it. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: This is a key idea of liberalism, opposed to any idea that we should abandon our own value to that of our state. I agree, but communitarians can subscribe to this too, while disagreeing that maximum freedom is the strategy to follow. |
7217 | The main argument for freedom is that interference with it is usually misguided [Mill] |
Full Idea: The strongest of all the arguments against the interference of the public with purely personal conduct is that, when it does interfere, the odds are that it interferes wrongly, and in the wrong place. | |
From: John Stuart Mill (On Liberty [1857], Ch.4) | |
A reaction: This is also a well known objection to capital punishment. Generalised, well established, legal interferences are perhaps more likely to get it right than ad hoc decisions about individuals by individual officials. |
7213 | Liberty arises at the point where people can freely and equally discuss things [Mill] |
Full Idea: Liberty, as a principle, has no application to any state of things anterior to the time when mankind have become capable of being improved by free and equal discussion. | |
From: John Stuart Mill (On Liberty [1857], Ch.1) | |
A reaction: There is a Victorian (and Enlightenment) optimism here which a glimpse of the freedoms of the early twenty-first century might dampen. I doubt if Mill expected British tabloid newspapers, or porn on cable TV. Education and freedom connect. |
20516 | Mill defends freedom as increasing happiness, but maybe it is an intrinsic good [Wolff,J on Mill] |
Full Idea: Mill has presented liberty as instrumentally valuable, as a way of achieving the greatest possible happiness in society. But perhaps he should have argued that liberty is an intrinsic good, good in itself. | |
From: comment on John Stuart Mill (On Liberty [1857]) by Jonathan Wolff - An Introduction to Political Philosophy (Rev) 4 'Intrinsic' | |
A reaction: If freedom is intrinsically good, does this leave us (as Wolff warned earlier) unable to defend its value? Freedom isn't an intrinsic good for infants, so why should it be so for adults? Good because it brings happiness, or fulfils our nature? |
20517 | Utilitarianism values liberty, but guides us on which ones we should have or not have [Mill, by Wolff,J] |
Full Idea: Utilitarianism provides an account of what liberties we should and should not have. Mill argues we should be free to compete in trade, but not to use another's property without consent. Thus he sets limits to liberty, while paying it great respect. | |
From: report of John Stuart Mill (On Liberty [1857]) by Jonathan Wolff - An Introduction to Political Philosophy (Rev) 4 'Intrinsic' |
7215 | True freedom is pursuing our own good, while not impeding others [Mill] |
Full Idea: The only freedom which deserves the name, is that of pursuing our own good in our own way, so long as we do not attempt to deprive others of theirs, or impede their efforts to obtain it. | |
From: John Stuart Mill (On Liberty [1857], Ch.1) | |
A reaction: This principle will probably lead up a Prisoner's Dilemma cul-de-sac. The only freedom which deserves the name is the collective agreed freedom of a whole community to live well, when citizens volunteer to restrict their individual freedoms. |
7220 | Restraint for its own sake is an evil [Mill] |
Full Idea: All restraint, qua restraint, is an evil. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: The ultimate justification for this is (presumably) utilitarian, but that would mean that there was nothing wrong with restraint if the person did not mind, or was not aware of the restraint. What is intrinsically wrong with restraint? |
7218 | Individuals are not accountable for actions which only concern themselves [Mill] |
Full Idea: My first maxim is that the individual is not accountable to society for his actions, in so far as these concern the interests of no person but himself. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: This is a key idea of liberalism, and one which communitarians have doubts about (because it is almost impossible to perform an action which is of no interest, in the short or long term, to others). I share these doubts. |
7221 | Blocking entry to an unsafe bridge does not infringe liberty, since no one wants unsafe bridges [Mill] |
Full Idea: An official could turn a person back from an unsafe bridge without infringeing their liberty; for liberty consists in doing what one desires, and he does not desire to fall into the river. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: Seems fair enough, but it justifies paternalist interference. The tricky one is where the official and the citizen disagree over what the citizen 'truly' desires. Asking people may involve too much time, but it could also involve too much effort. |
7223 | Pimping and running a gambling-house are on the border between toleration and restraint [Mill] |
Full Idea: A person being free to be a pimp, or to keep a gambling-house, lies on the exact boundary line between two principles, of toleration and of restraint. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: Nothing illuminates a philosopher's principles more than for them to specify cases that lie on their borderlines. Both professions seem, unfortunately, to lead people into worse activities, such as violent bullying, or theft. Tricky.. |
7219 | Society can punish actions which it believes to be prejudicial to others [Mill] |
Full Idea: My second maxim is that for actions that are prejudicial to the interests of others, the individual is accountable, and subject to social or legal punishment, if society believes that this is requisite for its protection. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: (wording compressed). The trouble with this would seem to be the possible disagreement between the individual and the society over whether the actions actually are prejudicial to others. It would justify a conservative society in being repressive. |
7226 | Benefits performed by individuals, not by government, help also to educate them [Mill] |
Full Idea: It is often desirable that beneficial things should be done by individuals, rather than by the government, as a means to their own mental education. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: This raises the important danger, which even those on the political left must acknowledge, of the 'nanny state'. It offers a nicely paternalistic, and even patronising reason for giving people freedom, just as a parent might to a child. |
7224 | We need individual opinions and conduct, and State education is a means to prevent that [Mill] |
Full Idea: Individuality of character, and diversity in opinions and modes of conduct, involves diversity of education; a general State education is a mere contrivance for moulding people to be exactly like one another. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: This strikes me as being particularly true with the advent in Britain of the National Curriculum in the early 1990s. However, if there is a pressure towards conformity in state education, private education is dominated by class and money. |
7225 | It is a crime to create a being who lacks the ordinary chances of a desirable existence [Mill] |
Full Idea: To bestow a life on someone which may be either a curse or a blessing, unless the being on whom it is to be bestowed will have at least the ordinary chances of a desirable existence, is a crime against that being. | |
From: John Stuart Mill (On Liberty [1857], Ch.5) | |
A reaction: This is the standard utilitarian attitude to engendering people. I think I have to agree. It is no argument against this to say that we value people with poor life prospects, once they have arrived. Altruism towards children may disguise selfish parents. |
7216 | The ethics of the Gospel has been supplemented by barbarous Old Testament values [Mill] |
Full Idea: To extract from the Gospel a body of ethical doctrine, has never been possible withouth eking it out from the Old Testament, that is, from a system elaborate indeed, but in many respects barbarous, and intended only for a barbarous people. | |
From: John Stuart Mill (On Liberty [1857], Ch.2) | |
A reaction: 'Barbarous' has a quaint Victorian ring to it, but his point is that the surviving teachings of Jesus are very thin and generalised. Christians would do better to expand their implications, than to borrow from the Old Testament. |