50 ideas
24084 | Seeing with other eyes is more egoism, but exploring other perspectives leads to objectivity [Nietzsche] |
Full Idea: Wanting to know things as they are - that alone is the good inclination: not seeing ..with other eyes; that would be merely a change of place of egoistic seeing. …Practise at seeing with other eyes, and without human relationships, hence objectively! | |
From: Friedrich Nietzsche (Unpublished Notebooks 1881-82 [1882], 11[013]) | |
A reaction: That Nietzsche thinks we should try to see things objectively will come as a bit of a shock to those who have him catalogued among the relativists. It's clear from other writings that he thinks (rightly) that perfect objectivity is unattainable. |
9847 | A contextual definition permits the elimination of the expression by a substitution [Dummett] |
Full Idea: The standard sense of a 'contextual definition' permits the eliminating of the defined expression, by transforming any sentence containing it into an equivalent one not containing it. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.11) | |
A reaction: So the whole definition might be eliminated by a single word, which is not equivalent to the target word, which is embedded in the original expression. Clearly contextual definitions have some problems |
24092 | I tell the truth, even if it is repulsive [Nietzsche] |
Full Idea: As a man I tell the truth, even the repulsive ones. | |
From: Friedrich Nietzsche (Unpublished Notebooks 1881-82 [1882], 12[86]) | |
A reaction: I wonder if even Nietzsche had his limits. He is quite coy about sexual matters, for example, before Freud and various sexual revolutions. To ruthlessly tell difficult truths strikes me as a scientific approach to the world. |
7785 | The use of plurals doesn't commit us to sets; there do not exist individuals and collections [Boolos] |
Full Idea: We should abandon the idea that the use of plural forms commits us to the existence of sets/classes… Entities are not to be multiplied beyond necessity. There are not two sorts of things in the world, individuals and collections. | |
From: George Boolos (To be is to be the value of a variable.. [1984]), quoted by Henry Laycock - Object | |
A reaction: The problem of quantifying over sets is notoriously difficult. Try http://plato.stanford.edu/entries/object/index.html. |
10699 | Does a bowl of Cheerios contain all its sets and subsets? [Boolos] |
Full Idea: Is there, in addition to the 200 Cheerios in a bowl, also a set of them all? And what about the vast number of subsets of Cheerios? It is haywire to think that when you have some Cheerios you are eating a set. What you are doing is: eating the Cheerios. | |
From: George Boolos (To be is to be the value of a variable.. [1984], p.72) | |
A reaction: In my case Boolos is preaching to the converted. I am particularly bewildered by someone (i.e. Quine) who believes that innumerable sets exist while 'having a taste for desert landscapes' in their ontology. |
9820 | In classical logic, logical truths are valid formulas; in higher-order logics they are purely logical [Dummett] |
Full Idea: For sentential or first-order logic, the logical truths are represented by valid formulas; in higher-order logics, by sentences formulated in purely logical terms. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch. 3) |
10225 | Monadic second-order logic might be understood in terms of plural quantifiers [Boolos, by Shapiro] |
Full Idea: Boolos has proposed an alternative understanding of monadic, second-order logic, in terms of plural quantifiers, which many philosophers have found attractive. | |
From: report of George Boolos (To be is to be the value of a variable.. [1984]) by Stewart Shapiro - Philosophy of Mathematics 3.5 |
10736 | Boolos showed how plural quantifiers can interpret monadic second-order logic [Boolos, by Linnebo] |
Full Idea: In an indisputable technical result, Boolos showed how plural quantifiers can be used to interpret monadic second-order logic. | |
From: report of George Boolos (To be is to be the value of a variable.. [1984], Intro) by Øystein Linnebo - Plural Quantification Exposed Intro |
10780 | Any sentence of monadic second-order logic can be translated into plural first-order logic [Boolos, by Linnebo] |
Full Idea: Boolos discovered that any sentence of monadic second-order logic can be translated into plural first-order logic. | |
From: report of George Boolos (To be is to be the value of a variable.. [1984], §1) by Øystein Linnebo - Plural Quantification Exposed p.74 |
10697 | Identity is clearly a logical concept, and greatly enhances predicate calculus [Boolos] |
Full Idea: Indispensable to cross-reference, lacking distinctive content, and pervading thought and discourse, 'identity' is without question a logical concept. Adding it to predicate calculus significantly increases the number and variety of inferences possible. | |
From: George Boolos (To be is to be the value of a variable.. [1984], p.54) | |
A reaction: It is not at all clear to me that identity is a logical concept. Is 'existence' a logical concept? It seems to fit all of Boolos's criteria? I say that all he really means is that it is basic to thought, but I'm not sure it drives the reasoning process. |
13671 | Second-order quantifiers are just like plural quantifiers in ordinary language, with no extra ontology [Boolos, by Shapiro] |
Full Idea: Boolos proposes that second-order quantifiers be regarded as 'plural quantifiers' are in ordinary language, and has developed a semantics along those lines. In this way they introduce no new ontology. | |
From: report of George Boolos (To be is to be the value of a variable.. [1984]) by Stewart Shapiro - Foundations without Foundationalism 7 n32 | |
A reaction: This presumably has to treat simple predicates and relations as simply groups of objects, rather than having platonic existence, or something. |
10267 | We should understand second-order existential quantifiers as plural quantifiers [Boolos, by Shapiro] |
Full Idea: Standard second-order existential quantifiers pick out a class or a property, but Boolos suggests that they be understood as a plural quantifier, like 'there are objects' or 'there are people'. | |
From: report of George Boolos (To be is to be the value of a variable.. [1984]) by Stewart Shapiro - Philosophy of Mathematics 7.4 | |
A reaction: This idea has potential application to mathematics, and Lewis (1991, 1993) 'invokes it to develop an eliminative structuralism' (Shapiro). |
10698 | Plural forms have no more ontological commitment than to first-order objects [Boolos] |
Full Idea: Abandon the idea that use of plural forms must always be understood to commit one to the existence of sets of those things to which the corresponding singular forms apply. | |
From: George Boolos (To be is to be the value of a variable.. [1984], p.66) | |
A reaction: It seems to be an open question whether plural quantification is first- or second-order, but it looks as if it is a rewriting of the first-order. |
7806 | Boolos invented plural quantification [Boolos, by Benardete,JA] |
Full Idea: Boolos virtually patented the new device of plural quantification. | |
From: report of George Boolos (To be is to be the value of a variable.. [1984]) by José A. Benardete - Logic and Ontology | |
A reaction: This would be 'there are some things such that...' |
9896 | A prime number is one which is measured by a unit alone [Dummett] |
Full Idea: A prime number is one which is measured by a unit alone. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], 7 Def 11) | |
A reaction: We might say that the only way of 'reaching' or 'constructing' a prime is by incrementing by one till you reach it. That seems a pretty good definition. 64, for example, can be reached by a large number of different routes. |
18255 | Addition of quantities is prior to ordering, as shown in cyclic domains like angles [Dummett] |
Full Idea: It is essential to a quantitative domain of any kind that there should be an operation of adding its elements; that this is more fundamental thaat that they should be linearly ordered by magnitude is apparent from cyclic domains like that of angles. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], 22 'Quantit') |
9895 | A number is a multitude composed of units [Dummett] |
Full Idea: A number is a multitude composed of units. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], 7 Def 2) | |
A reaction: This is outdated by the assumption that 0 and 1 are also numbers, but if we say one is really just the 'unit' which is preliminary to numbers, and 0 is as bogus a number as i is, we might stick with the original Greek distinction. |
9852 | We understand 'there are as many nuts as apples' as easily by pairing them as by counting them [Dummett] |
Full Idea: A child understands 'there are just as many nuts as apples' as easily by pairing them off as by counting them. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.12) | |
A reaction: I find it very intriguing that you could know that two sets have the same number, without knowing any numbers. Is it like knowing two foreigners spoke the same words, without understanding them? Or is 'equinumerous' conceptually prior to 'number'? |
9829 | The identity of a number may be fixed by something outside structure - by counting [Dummett] |
Full Idea: The identity of a mathematical object may sometimes be fixed by its relation to what lies outside the structure to which it belongs. It is more fundamental to '3' that if certain objects are counted, there are three of them. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch. 5) | |
A reaction: This strikes me as Dummett being pushed (by his dislike of the purely abstract picture given by structuralism) back to a rather empiricist and physical view of numbers, though he would totally deny that. |
9828 | Numbers aren't fixed by position in a structure; it won't tell you whether to start with 0 or 1 [Dummett] |
Full Idea: The number 0 is not differentiated from 1 by its position in a progression, otherwise there would be no difference between starting with 0 and starting with 1. That is enough to show that numbers are not identifiable just as positions in structures. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch. 5) | |
A reaction: This sounds conclusive, but doesn't feel right. If numbers are a structure, then where you 'start' seems unimportant. Where do you 'start' in St Paul's Cathedral? Starting sounds like a constructivist concept for number theory. |
9876 | Set theory isn't part of logic, and why reduce to something more complex? [Dummett] |
Full Idea: The two frequent modern objects to logicism are that set theory is not part of logic, or that it is of no interest to 'reduce' a mathematical theory to another, more complex, one. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.18) | |
A reaction: Dummett says these are irrelevant (see context). The first one seems a good objection. The second one less so, because whether something is 'complex' is a quite different issue from whether it is ontologically more fundamental. |
9884 | The distinction of concrete/abstract, or actual/non-actual, is a scale, not a dichotomy [Dummett] |
Full Idea: The distinction between concrete and abstract objects, or Frege's corresponding distinction between actual and non-actual objects, is not a sharp dichotomy, but resembles a scale upon which objects occupy a range of positions. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.18) | |
A reaction: This might seem right if you live (as Dummett chooses to) in the fog of language, but it surely can't be right if you think about reality. Is the Equator supposed to be near the middle of his scale? Either there is an equator, or there isn't. |
9869 | Realism is just the application of two-valued semantics to sentences [Dummett] |
Full Idea: Fully fledged realism depends on - indeed, may be identified with - an undiluted application to sentences of the relevant kind of straightforwards two-valued semantics. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.15) | |
A reaction: This is the sort of account you get from a whole-heartedly linguistic philosopher. Personally I would say that Dummett has got it precisely the wrong way round: I adopt a two-valued semantics because my metaphysics is realist. |
10700 | First- and second-order quantifiers are two ways of referring to the same things [Boolos] |
Full Idea: Ontological commitment is carried by first-order quantifiers; a second-order quantifier needn't be taken to be a first-order quantifier in disguise, having special items, collections, as its range. They are two ways of referring to the same things. | |
From: George Boolos (To be is to be the value of a variable.. [1984], p.72) | |
A reaction: If second-order quantifiers are just a way of referring, then we can see first-order quantifiers that way too, so we could deny 'objects'. |
9880 | Nominalism assumes unmediated mental contact with objects [Dummett] |
Full Idea: The nominalist superstition is based ultimately on the myth of the unmediated presentation of genuine concrete objects to the mind. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.18) | |
A reaction: Personally I am inclined to favour nominalism and a representative theory of perception, which acknowledges some 'mediation', but of a non-linguistic form. Any good theory here had better include animals, which seem to form concepts. |
9885 | The existence of abstract objects is a pseudo-problem [Dummett] |
Full Idea: The existence of abstract objects is a pseudo-problem. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.18) | |
A reaction: This remark follows after Idea 9884, which says the abstract/concrete distinction is a sliding scale. Personally I take the distinction to be fairly sharp, and it is therefore probably the single most important problem in the whole of human thought. |
9858 | Abstract objects nowadays are those which are objective but not actual [Dummett] |
Full Idea: Objects which are objective but not actual are precisely what are now called abstract objects. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.15) | |
A reaction: Why can there not be subjective abstract objects? 'My favourites are x, y and z'. 'I'll decide later what my favourites are'. 'I only buy my favourites - nothing else'. |
9859 | It is absurd to deny the Equator, on the grounds that it lacks causal powers [Dummett] |
Full Idea: If someone argued that assuming the existence of the Equator explains nothing, and it has no causal powers, so everything would be the same if it didn't exist, so we needn't accept its existence, we should gape at the crudity of the misunderstanding. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.15) | |
A reaction: Not me. I would gape if someone argued that latitude 55° 14' (and an infinity of other lines) exists for the same reasons (whatever they may be) that the Equator exists. A mode of description can't create an object. |
9860 | 'We've crossed the Equator' has truth-conditions, so accept the Equator - and it's an object [Dummett] |
Full Idea: 'We've crossed the Equator' is judged true if we are nearer the other Pole, so it not for philosophers to deny that the Earth has an equator, and we see that the Equator is not a concept or relation or function, so it must be classified as an object. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.15) | |
A reaction: A lovely example of linguistic philosophy in action (and so much the worse for that, I would say). A useful label here, I suggest (unoriginally, I think), is that we should label such an item a 'semantic object', rather than a real object in our ontology. |
9872 | Abstract objects need the context principle, since they can't be encountered directly [Dummett] |
Full Idea: To recognise that there is no objection in principle to abstract objects requires acknowledgement that some form of the context principle is correct, since abstract objects can neither be encountered nor presented. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.16) | |
A reaction: I take this to be an immensely important idea. I consider myself to be a philosopher of thought rather than a philosopher of language (Dummett's distinction, he being one of the latter). Thought connects to the world, but does it connect to abstracta? |
24089 | Essences are fictions needed for beings who represent things [Nietzsche] |
Full Idea: The true essence of things is a fiction of representing being, without which being is unable to represent. 11[330] Thinking must assert substance and identity because a knowing of complete flux is impossible. | |
From: Friedrich Nietzsche (Unpublished Notebooks 1881-82 [1882], 11[329]) | |
A reaction: I have defended (in my PhD) the thesis that the concept of essence is required for explanation. Do animals need the concept of essence in order to represent? I think people and animals ascribe essential natures to most things. |
9848 | Content is replaceable if identical, so replaceability can't define identity [Dummett, by Dummett] |
Full Idea: Husserl says the only ground for assuming the replaceability of one content by another is their identity; we are therefore not entitled to define their identity as consisting in their replaceability. | |
From: report of Michael Dummett (Frege philosophy of mathematics [1991]) by Michael Dummett - Frege philosophy of mathematics Ch.12 | |
A reaction: This is a direct challenge to Frege. Tricky to arbitrate, as it is an issue of conceptual priority. My intuition is with Husserl, but maybe the two are just benignly inerdefinable. |
9842 | Frege introduced criteria for identity, but thought defining identity was circular [Dummett] |
Full Idea: In his middle period Frege rated identity indefinable, on the ground that every definition must take the form of an identity-statement. Frege introduced the notion of criterion of identity, which has been widely used by analytical philosophers. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.10) | |
A reaction: The objection that attempts to define identity would be circular sounds quite plausible. It sounds right to seek a criterion for type-identity (in shared properties or predicates), but token-identity looks too fundamental to give clear criteria. |
24090 | Our inclinations would not conflict if we were a unity; we imagine unity for our multiplicity [Nietzsche] |
Full Idea: How is it that we satisfy our stronger inclinations at the expense of our weaker inclinations? - In itself, if we were a unity, this split could not exist. In fact we are a multiplicity that has imagined a unity for itself. | |
From: Friedrich Nietzsche (Unpublished Notebooks 1881-82 [1882], 12[35]) | |
A reaction: Plato had the same thought, but stopped at three parts, rather than a multiplicity. What Nietzsche fails to say, I think, is that this 'imagined' unity of the mind is not optional, and obviously has a real link to the one body and the one life. |
9849 | Maybe a concept is 'prior' to another if it can be defined without the second concept [Dummett] |
Full Idea: One powerful argument for a thesis that one notion is conceptually prior to another is the possibility of defining the first without reference to the second. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.12) | |
A reaction: You'd better check whether you can't also define the second without reference to the first before you rank their priority. And maybe 'conceptual priority' is conceptually prior to 'definition' (i.e. definition needs a knowledge of priority). Help! |
9850 | An argument for conceptual priority is greater simplicity in explanation [Dummett] |
Full Idea: An argument for conceptual priority is greater simplicity in explanation. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.12) | |
A reaction: One might still have to decide priority between two equally simple (or complex) concepts. I begin to wonder whether 'priority' has any other than an instrumental meaning (according to which direction you wish to travel - is London before Edinburgh?). |
9873 | Abstract terms are acceptable as long as we know how they function linguistically [Dummett] |
Full Idea: To recognise abstract terms as perfectly proper items of a vocabulary depends upon allowing that all that is necessary for the lawful introduction of a range of expressions into the language is a coherent account of how they are to function in sentences. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.16) | |
A reaction: Why can't the 'coherent account' of the sentences include the fact that there must be something there for the terms to refer to? How else are we to eliminate nonsense words which obey good syntactical rules? Cf. Idea 9872. |
9993 | There is no reason why abstraction by equivalence classes should be called 'logical' [Dummett, by Tait] |
Full Idea: Dummett uses the term 'logical abstraction' for the construction of the abstract objects as equivalence classes, but it is not clear why we should call this construction 'logical'. | |
From: report of Michael Dummett (Frege philosophy of mathematics [1991]) by William W. Tait - Frege versus Cantor and Dedekind n 14 | |
A reaction: This is a good objection, and Tait offers a much better notion of 'logical abstraction' (as involving preconditions for successful inference), in Idea 9981. |
9857 | We arrive at the concept 'suicide' by comparing 'Cato killed Cato' with 'Brutus killed Brutus' [Dummett] |
Full Idea: We arrive at the concept of suicide by considering both occurrences in the sentence 'Cato killed Cato' of the proper name 'Cato' as simultaneously replaceable by another name, say 'Brutus', and so apprehending the pattern common to both sentences. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.14) | |
A reaction: This is intended to illustrate Frege's 'logical abstraction' technique, as opposed to wicked psychological abstraction. The concept of suicide is the pattern 'x killed x'. This is a crucial example if we are to understand abstraction... |
9833 | To abstract from spoons (to get the same number as the forks), the spoons must be indistinguishable too [Dummett] |
Full Idea: To get units by abstraction, units arrived at by abstraction from forks must the identical to that abstracted from spoons, with no trace of individuality. But if spoons can no longer be differentiated from forks, they can't differ from one another either. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch. 8) | |
A reaction: [compressed] Dummett makes the point better than Frege did. Can we 'think of a fork insofar as it is countable, ignoring its other features'? What are we left thinking of? Frege says it must still be the whole fork. 'Nice fork, apart from the colour'. |
9836 | Fregean semantics assumes a domain articulated into individual objects [Dummett] |
Full Idea: A Fregean semantics assumes a domain already determinately articulated into individual objects. | |
From: Michael Dummett (Frege philosophy of mathematics [1991], Ch. 8) | |
A reaction: A more interesting criticism than most of Dummett's other challenges to the Frege/Davidson view. I am beginning to doubt whether the semantics and the ontology can ever be divorced from the psychology, of thought, interests, focus etc. |
24087 | People who miss beauty seek the sublime, where even the ugly shows its 'beauty' [Nietzsche] |
Full Idea: Whoever does not achieve the beautiful seeks the wildly sublime, because there even the ugly can show its 'beauty'. Likewise we seek the wildly sublime morality. | |
From: Friedrich Nietzsche (Unpublished Notebooks 1881-82 [1882], 11[049]) | |
A reaction: Is the 'we' here Nietzsche, or the herd? The former, I guess, since some the values he likes seem rather ugly to me. He is a fan of war, for example. I'm guessing that massive destruction is sublime but ugly. |
24091 | The sublimity of nature which dwarfs us was a human creation [Nietzsche] |
Full Idea: This beauty and sublimity of nature, before which every human being seems small, was first imposed on nature by us. | |
From: Friedrich Nietzsche (Unpublished Notebooks 1881-82 [1882], 12[38]) | |
A reaction: I was struck when I was 10 with how indifferent to a landscape I was, when my mother told me it was 'beautiful'. Five years later I saw it differently. I assume nature is not intrinsically sublime. Dwarfed by our own concept is a bit odd. |
24093 | We can aspire to greatness by creating new functions for ourselves [Nietzsche] |
Full Idea: To see the new greatness not above oneself, not outside oneself, but to make a new function from it. | |
From: Friedrich Nietzsche (Unpublished Notebooks 1881-82 [1882], 13[19]) | |
A reaction: Thus we might combine the Aristotelian and the existentialist views! Do we discover our function or invent it? Anyone who acquires an expertise is creating a new function for themselves, presumably with a high value. |
24085 | For absolute morality a goal for mankind is needed [Nietzsche] |
Full Idea: I deny absolute morality because I do not know an absolute goal of mankind. | |
From: Friedrich Nietzsche (Unpublished Notebooks 1881-82 [1882], 11[037]) | |
A reaction: Christianity dreams of union of souls with God (clustering around God like goldfish to food, according to Dante). That is an absolute goal, justifying an absolute morality. If Aristotelians could identify human nature, its flourishing might be absolute. |
24094 | Humans are vividly aware of short-term effects, and almost ignorant of the long-term ones [Nietzsche] |
Full Idea: How weakly human beings feel responsible for their indirect and distant effects! And how cruelly and exaggeratedly the closest effect that we exert pounces on us - the effect we see, for which our myopic vision is still just sharp enough! | |
From: Friedrich Nietzsche (Unpublished Notebooks 1881-82 [1882], 15[11]) | |
A reaction: This strikes me as both accurate and important, because consequentialist ethics is largely committed to judging by a very distorted image of their own objective. |
24086 | The goal is to settle human beings, like other animals, but humans are still changeable [Nietzsche] |
Full Idea: Obviously the goal is to make human beings as steady and firm as most animal species; they have adapted to the conditions of the earth etc. and do not change essentially. The human being is still changeable - is still becoming. | |
From: Friedrich Nietzsche (Unpublished Notebooks 1881-82 [1882], 11[044]) | |
A reaction: I favour an Aristotelian view, based on the flourishing of human nature, but this thought obviously challenges such a view. Great changes to a culture can make some difference to the apparent nature of people. |
24088 | See our present lives as eternal! Religions see it as fleeting, and aim at some different life [Nietzsche] |
Full Idea: Let us press the image of eternity on our life! This thought contains more than all religions that despise this life as fleeting and taught us to look toward an unspecified different life. | |
From: Friedrich Nietzsche (Unpublished Notebooks 1881-82 [1882], 11[159]) | |
A reaction: This is the best statement of the idea of eternal recurrence I have so far found. His ideal is to design a life for ourselves which we would be happy to see endlessly repeated. A lot of thought would have to go into that! |
24095 | Our growth is too subtle to perceive, and long events are too slow for us to grasp [Nietzsche] |
Full Idea: The slowness of the events in the history of human beings is not suited to the human sense of time - and the subtlety and smallness of all growth defies human vision. | |
From: Friedrich Nietzsche (Unpublished Notebooks 1881-82 [1882], 15[41]) | |
A reaction: The only way we can study history is by 'periods'. It is as if English history has its slate wiped clean in 1066, 1485, 1603 and 1689. All historians know that the reality of it all is totally beyond our grasp. |
18257 | Why should the limit of measurement be points, not intervals? [Dummett] |
Full Idea: By what right do we assume that the limit of measurement is a point, and not an interval? | |
From: Michael Dummett (Frege philosophy of mathematics [1991], 22 'Quantit') |