46 ideas
| 7623 | For ancient Greeks being wise was an ethical value [Putnam] |
| Full Idea: An ancient Greek would have said that being wise is an ethical value. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.6) | |
| A reaction: This is instantly appealing, but since the Enlightenment we are under an obligation to attempt to justify absolutely everything, including the value of wisdom. I'm thinking that it only has value if it leads to eudaimonia. |
| 13838 | A decent modern definition should always imply a semantics [Hacking] |
| Full Idea: Today we expect that anything worth calling a definition should imply a semantics. | |
| From: Ian Hacking (What is Logic? [1979], §10) | |
| A reaction: He compares this with Gentzen 1935, who was attempting purely syntactic definitions of the logical connectives. |
| 4714 | Putnam's epistemic notion of truth replaces the realism of correspondence with ontological relativism [Putnam, by O'Grady] |
| Full Idea: Putnam replaces a correspondence theory of truth with an epistemic notion of truth - truth is idealized rational acceptability. The correspondence theory is committed to realism, but his allows ontological relativism. | |
| From: report of Hilary Putnam (Reason, Truth and History [1981]) by Paul O'Grady - Relativism Ch.3 | |
| A reaction: This seems to be part of a slide by Putnam away from realism towards pragmatism. As a robust and defiant realist, this always strikes me as the road to hell. |
| 7617 | Before Kant, all philosophers had a correspondence theory of truth [Putnam] |
| Full Idea: Before Kant it is impossible to find any philosopher who did not have a correspondence theory of truth. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.3) | |
| A reaction: I don't believe this is true of Descartes. See ideas 2266 and 4298. Truth is 'clear and distinct' conceptions, but if you enlarge (and maybe socialise) 'clear' you get coherent. Descartes firmly avoids correspondence, because he can't trust 'facts'. |
| 4716 | The correspondence theory is wrong, because there is no one correspondence between reality and fact [Putnam, by O'Grady] |
| Full Idea: Putnam argues that theory does not correspond to reality, because there are myriad correspondences possible, and we cannot single out "the" relation of correspondence. | |
| From: report of Hilary Putnam (Reason, Truth and History [1981]) by Paul O'Grady - Relativism Ch.3 | |
| A reaction: This obviously depends on views about reference and meaning. I don't see the problem in simple cases, which is all the correspondence theory needs. Complex cases, like chemistry, may well have ambiguities, but so what? |
| 7616 | Truth is an idealisation of rational acceptability [Putnam] |
| Full Idea: Truth is an idealisation of rational acceptability; we speak as if there were such things as epistemically ideal conditions, and we call a statement 'true' if it would be justified under such conditions. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.3) | |
| A reaction: The second part makes human beings sound stupid (which they are not), but the first part is right, and incredibly important. Peirce is behind Putnam's thought. Truth is the target of belief. It isn't a nonsense just because we can't be infallible. |
| 13833 | 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking] |
| Full Idea: 'Dilution' (or 'Thinning') provides an essential contrast between deductive and inductive reasoning; for the introduction of new premises may spoil an inductive inference. | |
| From: Ian Hacking (What is Logic? [1979], §06.2) | |
| A reaction: That is, inductive logic (if there is such a thing) is clearly non-monotonic, whereas classical inductive logic is monotonic. |
| 13834 | Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking] |
| Full Idea: If A |- B and B |- C, then A |- C. This generalises to: If Γ|-A,Θ and Γ,A |- Θ, then Γ |- Θ. Gentzen called this 'cut'. It is the transitivity of a deduction. | |
| From: Ian Hacking (What is Logic? [1979], §06.3) | |
| A reaction: I read the generalisation as 'If A can be either a premise or a conclusion, you can bypass it'. The first version is just transitivity (which by-passes the middle step). |
| 13835 | Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking] |
| Full Idea: Only the cut rule can have a conclusion that is less complex than its premises. Hence when cut is not used, a derivation is quite literally constructive, building up from components. Any theorem obtained by cut can be obtained without it. | |
| From: Ian Hacking (What is Logic? [1979], §08) |
| 13845 | The various logics are abstractions made from terms like 'if...then' in English [Hacking] |
| Full Idea: I don't believe English is by nature classical or intuitionistic etc. These are abstractions made by logicians. Logicians attend to numerous different objects that might be served by 'If...then', like material conditional, strict or relevant implication. | |
| From: Ian Hacking (What is Logic? [1979], §15) | |
| A reaction: The idea that they are 'abstractions' is close to my heart. Abstractions from what? Surely 'if...then' has a standard character when employed in normal conversation? |
| 13840 | First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking] |
| Full Idea: First-order logic is the strongest complete compact theory with a Löwenheim-Skolem theorem. | |
| From: Ian Hacking (What is Logic? [1979], §13) |
| 13844 | A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking] |
| Full Idea: Henkin proved that there is no first-order treatment of branching quantifiers, which do not seem to involve any idea that is fundamentally different from ordinary quantification. | |
| From: Ian Hacking (What is Logic? [1979], §13) | |
| A reaction: See Hacking for an example of branching quantifiers. Hacking is impressed by this as a real limitation of the first-order logic which he generally favours. |
| 13842 | Second-order completeness seems to need intensional entities and possible worlds [Hacking] |
| Full Idea: Second-order logic has no chance of a completeness theorem unless one ventures into intensional entities and possible worlds. | |
| From: Ian Hacking (What is Logic? [1979], §13) |
| 13837 | With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking] |
| Full Idea: My doctrine is that the peculiarity of the logical constants resides precisely in that given a certain pure notion of truth and consequence, all the desirable semantic properties of the constants are determined by their syntactic properties. | |
| From: Ian Hacking (What is Logic? [1979], §09) | |
| A reaction: He opposes this to Peacocke 1976, who claims that the logical connectives are essentially semantic in character, concerned with the preservation of truth. |
| 13839 | Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking] |
| Full Idea: For some purposes the variables of first-order logic can be regarded as prepositions and place-holders that could in principle be dispensed with, say by a system of arrows indicating what places fall in the scope of which quantifier. | |
| From: Ian Hacking (What is Logic? [1979], §11) | |
| A reaction: I tend to think of variables as either pronouns, or as definite descriptions, or as temporary names, but not as prepositions. Must address this new idea... |
| 14203 | Intension is not meaning, as 'cube' and 'square-faced polyhedron' are intensionally the same [Putnam] |
| Full Idea: Intension cannot be identified with meaning. ..'Cube' and 'regular polyhedron with six square faces' are logically equivalent predicates. The intension is the same (the function giving the cubes in any possible world) but there is a difference of meaning. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.2) |
| 14207 | If cats equal cherries, model theory allows reinterpretation of the whole language preserving truth [Putnam] |
| Full Idea: If the number of cats happens to equal the cherries, then it follows from the theory of models that there is a reinterpretation of the entire language that leaves all sentences unchanged in truth value while permuting the extensions of 'cat' and 'cherry'. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.2) | |
| A reaction: This horrifying result seems to come simply from the fact that there is an isomorphism between two models, which in turn seems to rest largely on the cardinality of the models. There seems to be something wrong with model theory here (?). |
| 13843 | If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking] |
| Full Idea: A Löwenheim-Skolem theorem holds for anything which, on my delineation, is a logic. | |
| From: Ian Hacking (What is Logic? [1979], §13) | |
| A reaction: I take this to be an unusually conservative view. Shapiro is the chap who can give you an alternative view of these things, or Boolos. |
| 14214 | If we try to cure the abundance of theories with causal links, this is 'just more theory' [Putnam, by Lewis] |
| Full Idea: If we try to base determinate reference on natural causal connection, Putnam says this is just more theory, as subject as any theory to overabundant, conflicting intended interpretations. | |
| From: report of Hilary Putnam (Reason, Truth and History [1981]) by David Lewis - Putnam's Paradox 'Why Are' | |
| A reaction: This is the 1981 Putnam, moving away from the realism that was implicit in the original causal theory of reference developed by himself and Kripke. His 'just more theory' is the slogan of Putnam's later anti-realism. |
| 14205 | The sentence 'A cat is on a mat' remains always true when 'cat' means cherry and 'mat' means tree [Putnam] |
| Full Idea: The sentence 'A cat is on a mat' can be reinterpreted so that in the actual world 'cat' refers to cherries and 'mat' refers to trees, without affecting the truth-value of the sentence in any possible world. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.2) | |
| A reaction: This simple suggestion is the basis of a notorious argument in favour of anti-realism. See D.Lewis's 'Putnam's Paradox'. It tracks back to Skolem's doubts about whether infinitary mathematics is possible. Putnam's conclusion sounds daft. |
| 7610 | A fact is simply what it is rational to accept [Putnam] |
| Full Idea: I propose that the only criterion for what is a fact is what it is rational to accept. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Pref) | |
| A reaction: An epistemological-ontological confusion here. The concept of a fact is of something which is the case quite independently of our criteria for believing it. There are facts which are unknowable for humans. It is, of course, rational to accept facts. |
| 7618 | Very nominalistic philosophers deny properties, though scientists accept them [Putnam] |
| Full Idea: Some philosophers are so nominalistic that they would deny the existence of such entities as 'properties' altogether; but science itself does not hesitate to talk freely of properties. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.3) | |
| A reaction: Maybe scientists aren't very good at ontology? They talk about forces and energy, but don't seem to know what they are. I am inclined to think that we must include properties in the working ontology of humans, but not into strict physics. |
| 12132 | Indiscernibility is a necessary and sufficient condition for identity [Brody] |
| Full Idea: Enduring objects should be taken as fundamental in an ontology, and for all such objects indiscernibility is both a necessary and sufficient condition for identity. | |
| From: Baruch Brody (Identity and Essence [1980], 3) | |
| A reaction: Brody offers a substantial defence, but I don't find it plausible. Apart from Black's well known twin spheres example (Idea 10195), discernibility is relative to the powers of the observer. Two similar people in the mist aren't thereby identical. |
| 15834 | Brody bases sortal essentialism on properties required throughout something's existence [Brody, by Mackie,P] |
| Full Idea: Brody bases sortal essentialism on the notion of a property that an individual must possess throughout its existence if it possesses it at any time in its existence. | |
| From: report of Baruch Brody (Identity and Essence [1980]) by Penelope Mackie - How Things Might Have Been 7.1 | |
| A reaction: Brody tends to treat categories as properties, which I dislike. How do you assess 'must' here? A person may possess a mole throughout life without it being essential. |
| 12140 | Modern emphasis is on properties had essentially; traditional emphasis is on sort-defining properties [Brody] |
| Full Idea: The modern emphasis has been on the connection between essential properties and the properties that an object must have essentially. But traditionally there is also the connection between essential properties and the sort of thing that it is. | |
| From: Baruch Brody (Identity and Essence [1980], 5.6) | |
| A reaction: These are the modal essence and the definitional essence. My view is that he has missed out a crucial third (Aristotelian) view, which is that essences are explanatory. This third view can subsume the other two. |
| 11895 | A sortal essence is a property which once possessed always possessed [Brody, by Mackie,P] |
| Full Idea: Brody bases sortal essentialism on the notion of a property that an individual must possess throughout its existence if it possesses it at any time in its existence. ...'Once an F, always an F'. ...Being a parrot is not a temporary occupation. | |
| From: report of Baruch Brody (Identity and Essence [1980]) by Penelope Mackie - How Things Might Have Been 7.1 | |
| A reaction: Hm. Would being less than fifty metres tall qualify as a sortal essence, for a giraffe or a uranium rod? If there is one thing an essential property should be, it is important. How do we assess importance? By explanatory power! Watch this space. |
| 12141 | Maybe essential properties are those which determine a natural kind? [Brody] |
| Full Idea: We can advance the thesis that all essential properties either determine a natural kind or are part of an essential property that does determine a natural kind. | |
| From: Baruch Brody (Identity and Essence [1980]) | |
| A reaction: A useful clear statement of the view. I am opposed to it, because I take it to be of the essence of Socrates that he is philosophical, but humans are not essentially philosophical, and philosophers are unlikely to be a natural kind. |
| 12137 | De re essentialism standardly says all possible objects identical with a have a's essential properties [Brody] |
| Full Idea: To say that an object a has a property P essentially is to say that it has P, and in all of certain worlds (all possible, all in which something identical with it exists, ...) the object identical with it has P. This is the standard de re interpretation. | |
| From: Baruch Brody (Identity and Essence [1980], 5.4) | |
| A reaction: This view always has to be qualified by excluding trivially necessary properties, but that exclusion shows clearly that the notion of essential is more concerned with non-triviality than it is with necessity. |
| 12142 | Essentially, a has P, always had P, must have had P, and has never had a future without P [Brody] |
| Full Idea: 'a has property P essentially' means 'a has P, a always had P, there is no possible past in which P exists without P, and there is no moment of time at which a has had P and at which there is a possible future in which a exists without P' | |
| From: Baruch Brody (Identity and Essence [1980], 6) | |
| A reaction: This is Brody's own final account of essentialism. This is a carefully qualified form of the view that essential properties are, on the whole, the necessary properties, which view I take to be fundamentally mistaken. |
| 12143 | An object having a property essentially is equivalent to its having it necessarily [Brody] |
| Full Idea: An object having a property essentially is equivalent to its having it necessarily. | |
| From: Baruch Brody (Identity and Essence [1980], 6.1) | |
| A reaction: This strikes me as blatantly false. Personally I am toying with the very unorthodox view that essential properties are not at all necessary, and that something can retain its identity while changing its essential character. A philosopher with Alzheimers. |
| 12144 | Essentialism is justified if the essential properties of things explain their other properties [Brody] |
| Full Idea: The reasonableness of the essentialist hypothesis will be proportional to the extent that we can, as a result, use a's possession of P to explain a's other properties, ...and there is an inability to explain otherwise why a has P. | |
| From: Baruch Brody (Identity and Essence [1980], 6.3) | |
| A reaction: Brody as a rather liberal notion of properties. I would hope that we can do rather more than explain a's non-essential properties. If the non-essential properties were entailed by the essential ones, would they not then also be essential? |
| 12139 | Mereological essentialism says that every part that ensures the existence is essential [Brody] |
| Full Idea: Mereological essentialism (whose leading advocate is Chisholm) says that for every x and y, if x is ever part of y, then y is necessarily such that x is part of y at any time that y exists. | |
| From: Baruch Brody (Identity and Essence [1980], 5.6) | |
| A reaction: This sounds implausible, especially given the transitivity of parthood. Not only are the planks that constitute Theseus's Ship now essential to it, but all the parts of the planks, every last chip, are as well. |
| 12135 | Interrupted objects have two first moments of existence, which could be two beginnings [Brody] |
| Full Idea: If 'beginning of existence' meant 'first moment of existence after a period of nonexistence', then objects with interrupted existence have two beginnings of existence. | |
| From: Baruch Brody (Identity and Essence [1980], 4.1) | |
| A reaction: One might still maintain that the first beginning was essential to the object, since that is the event that defined it - and that would clarify the reason why we are supposed to think the origins are essential. I say the origin explains it. |
| 12130 | a and b share all properties; so they share being-identical-with-a; so a = b [Brody] |
| Full Idea: Suppose that a and b have all of their properties in common. a certainly has the property of-being-identical-with-a. So, by supposition, does b. Then a = b. | |
| From: Baruch Brody (Identity and Essence [1980], 1.2) | |
| A reaction: Brody defends this argument, and seems to think that it proves the identity of indiscernibles. As far as I can see it totally begs the question, since we can only assume that both have the property of being-identical-with-a if we have assumed a = b. |
| 4718 | If necessity is always relative to a description in a language, then there is only 'de dicto' necessity [Putnam, by O'Grady] |
| Full Idea: Putnam endorses the view that necessity is relative to a description, so there is only necessity 'de dicto': relative to language, not to reality. | |
| From: report of Hilary Putnam (Reason, Truth and History [1981]) by Paul O'Grady - Relativism Ch.3 | |
| A reaction: Even a realist must take this proposal seriously. The facts may contain de re necessities, but we could be very sceptical about our capacity to know them. Personally I enjoy speculating about de re necessities. They can't stop you. |
| 12138 | Identity across possible worlds is prior to rigid designation [Brody] |
| Full Idea: Identity across possible worlds is prior to rigid designation. | |
| From: Baruch Brody (Identity and Essence [1980], 5.4) | |
| A reaction: An interesting view. We might stipulate that any possible Aristotle is 'our Aristotle', but you would still need criteria for deciding which possible Aristotle's would qualify. Long-frozen Aristotles, stupid Aristotles, alien Aristotle's, deformed... |
| 7620 | Some kind of objective 'rightness' is a presupposition of thought itself [Putnam] |
| Full Idea: What the relativist fails to see is that it is a presupposition of thought itself that some kind of objective 'rightness' exists. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.5) | |
| A reaction: This may be the key objection to relativism. If you have a frame of reference, is it a good one? If you have a new perspective, is it better than your old one? Is the culture you live in confused or clear-thinking? Jokes and metaphors rely on truth. |
| 14204 | Naïve operationalism would have meanings change every time the tests change [Putnam] |
| Full Idea: On a naïve operationalist account every time a new way of testing whether a substance is really gold is discovered, the meaning and reference of 'gold' undergoes a change. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.2) |
| 7611 | Rationality is one part of our conception of human flourishing [Putnam] |
| Full Idea: Our notion of rationality is, at bottom, just one part of our conception of human flourishing, our idea of the good. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Pref) | |
| A reaction: This looks like the beginnings of virtue epistemology, since rationality will have criteria, which would seem to be virtues. I find this idea appealing, both as a view of rationality, and as a view of the human good. |
| 14200 | 'Water' on Twin Earth doesn't refer to water, but no mental difference can account for this [Putnam] |
| Full Idea: The word 'water' used on Twin Earth refers not to water but to this other liquid (XYZ). Yet there is no relevant difference in the mental state of Twin Earth speakers and speakers on Earth (in 1750) to account for this difference of reference. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.2) | |
| A reaction: In this world, if you and I separately meet twins, and I think about this twin while you think about that one, our mental states are different even if they are indistinguishable. I know I'm thinking about my twin, not yours. Indexicals. |
| 7612 | Reference is social not individual, because we defer to experts when referring to elm trees [Putnam] |
| Full Idea: My concept of an elm tree is exactly the same as my concept of a beech tree (I blush to confess), which shows that the determination of reference is social and not individual - both you and I defer to experts who can tell elms from beeches. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.1) | |
| A reaction: If I said 'that tree looks nice' I wouldn't be deferring to experts. Nor if I said 'that tree, which I take to be an elm, looks nice'. If I am an expert I don't defer to experts. |
| 7613 | Concepts are (at least in part) abilities and not occurrences [Putnam] |
| Full Idea: Concepts are (at least in part) abilities and not occurrences. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.1) | |
| A reaction: This seems to be building on the idea that meaning is use, and also arises from a background of pragmatism. Perhaps a concept is an acquaintance with a node in platonic space? Lots of abilities aren't concepts, so what distinguishes the concepts? |
| 14202 | Neither individual nor community mental states fix reference [Putnam] |
| Full Idea: Mental state (in either the individualistic or the collective sense) does not fix reference. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.2) | |
| A reaction: The idea that communities fix reference seems to me plausible. See Tyler Burge on this. |
| 14201 | Maybe the total mental state of a language community fixes the reference of a term [Putnam] |
| Full Idea: One might concede that the reference of a person's term isn't fixed by his individual mental state, but insist that the total mental state of all the members of the language community fixes the reference of the term. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.2) | |
| A reaction: I like this reading of the problem, though Putnam himself prefers to say that things fix the reference. I take reference to be a human action, not a natural causal relation. Animals connecting thought to object may not count as reference at all. |
| 14206 | There are infinitely many interpretations of a sentence which can all seem to be 'correct' [Putnam] |
| Full Idea: There are always infinitely many different interpretations of the predicates of a language which assign 'correct' truth-values to the sentences in all possible worlds, no matter how those 'correct' truth-values are singled out. | |
| From: Hilary Putnam (Reason, Truth and History [1981], Ch.2) | |
| A reaction: Putnam says that he is using this argument from model theory to endorse the scepticism about 'gavagai' that Quine expressed in 1960. It is based on the ideas of Skolem, who was a renegade philosopher of mathematics. See Tim Button. |
| 7624 | The word 'inconsiderate' nicely shows the blurring of facts and values [Putnam] |
| Full Idea: The use of the word 'inconsiderate' seems to me a very fine example of the way in which the fact/value distinction is hopelessly fuzzy in the real world and in the real language. | |
| From: Hilary Putnam (Reason, Truth and History [1981]) | |
| A reaction: Interesting, but not much of an argument. What would Nietzsche say? Was Agamemnon morally deficient because we might think him 'inconsiderate'? |