57 ideas
| 7454 | Gassendi is the first great empiricist philosopher [Hacking] |
| Full Idea: Gassendi is the first in the great line of empiricist philosophers that gradually came to dominate European thought. | |
| From: Ian Hacking (The Emergence of Probability [1975], Ch.5) | |
| A reaction: Epicurus, of course, was clearly an empiricist. British readers should note that Gassendi was not British. |
| 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. |
| 3593 | The only way to specify the corresponding fact is asserting the sentence [Williams,M] |
| Full Idea: The trouble with appeal to facts in the correspondence theory is that, in general, we have no way of indicating what fact a sentence, when true, corresponds to other than asserting the sentence. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch.12) |
| 3585 | Coherence needs positive links, not just absence of conflict [Williams,M] |
| Full Idea: It is often claimed that coherence is more than 'absence of conflict' between beliefs; it also involves 'positive connections'. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch.10) |
| 3584 | Justification needs coherence, while truth might be ideal coherence [Williams,M] |
| Full Idea: Contemporary coherence theorists are advancing a theory of justification, not of truth, …with those who argue that truth is also coherence explaining it in terms of ideal coherence, or coherence at the limit of enquiry. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch.10) |
| 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) |
| 3599 | Deduction shows entailments, not what to believe [Williams,M] |
| Full Idea: The rules of deduction are rules of entailment, not rules of inference. They tell us what follows from what, not what to believe on the basis of what. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch.18) |
| 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... |
| 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. |
| 16062 | A necessary relation between fact-levels seems to be a further irreducible fact [Lynch/Glasgow] |
| Full Idea: It seems unavoidable that the facts about logically necessary relations between levels of facts are themselves logically distinct further facts, irreducible to the microphysical facts. | |
| From: Lynch,MP/Glasgow,JM (The Impossibility of Superdupervenience [2003], C) | |
| A reaction: I'm beginning to think that rejecting every theory of reality that is proposed by carefully exposing some infinite regress hidden in it is a rather lazy way to do philosophy. Almost as bad as rejecting anything if it can't be defined. |
| 16061 | If some facts 'logically supervene' on some others, they just redescribe them, adding nothing [Lynch/Glasgow] |
| Full Idea: Logical supervenience, restricted to individuals, seems to imply strong reduction. It is said that where the B-facts logically supervene on the A-facts, the B-facts simply re-describe what the A-facts describe, and the B-facts come along 'for free'. | |
| From: Lynch,MP/Glasgow,JM (The Impossibility of Superdupervenience [2003], C) | |
| A reaction: This seems to be taking 'logically' to mean 'analytically'. Presumably an entailment is logically supervenient on its premisses, and may therefore be very revealing, even if some people think such things are analytic. |
| 16060 | Nonreductive materialism says upper 'levels' depend on lower, but don't 'reduce' [Lynch/Glasgow] |
| Full Idea: The root intuition behind nonreductive materialism is that reality is composed of ontologically distinct layers or levels. …The upper levels depend on the physical without reducing to it. | |
| From: Lynch,MP/Glasgow,JM (The Impossibility of Superdupervenience [2003], B) | |
| A reaction: A nice clear statement of a view which I take to be false. This relationship is the sort of thing that drives people fishing for an account of it to use the word 'supervenience', which just says two things seem to hang out together. Fluffy materialism. |
| 16064 | The hallmark of physicalism is that each causal power has a base causal power under it [Lynch/Glasgow] |
| Full Idea: Jessica Wilson (1999) says what makes physicalist accounts different from emergentism etc. is that each individual causal power associated with a supervenient property is numerically identical with a causal power associated with its base property. | |
| From: Lynch,MP/Glasgow,JM (The Impossibility of Superdupervenience [2003], n 11) | |
| A reaction: Hence the key thought in so-called (serious, rather than self-evident) 'emergentism' is so-called 'downward causation', which I take to be an idle daydream. |
| 7447 | Probability was fully explained between 1654 and 1812 [Hacking] |
| Full Idea: There is hardly any history of probability to record before Pascal (1654), and the whole subject is very well understood after Laplace (1812). | |
| From: Ian Hacking (The Emergence of Probability [1975], Ch.1) | |
| A reaction: An interesting little pointer on the question of whether the human race is close to exhausting all the available intellectual problems. What then? |
| 7448 | Probability is statistical (behaviour of chance devices) or epistemological (belief based on evidence) [Hacking] |
| Full Idea: Probability has two aspects: the degree of belief warranted by evidence, and the tendency displayed by some chance device to produce stable relative frequencies. These are the epistemological and statistical aspects of the subject. | |
| From: Ian Hacking (The Emergence of Probability [1975], Ch.1) | |
| A reaction: The most basic distinction in the subject. Later (p.124) he suggests that the statistical form (known as 'aleatory' probability) is de re, and the other is de dicto. |
| 7449 | Epistemological probability based either on logical implications or coherent judgments [Hacking] |
| Full Idea: Epistemological probability is torn between Keynes etc saying it depends on the strength of logical implication, and Ramsey etc saying it is personal judgement which is subject to strong rules of internal coherence. | |
| From: Ian Hacking (The Emergence of Probability [1975], Ch.2) | |
| A reaction: See Idea 7449 for epistemological probability. My immediate intuition is that the Ramsey approach sounds much more plausible. In real life there are too many fine-grained particulars involved for straight implication to settle a probability. |
| 3591 | We could never pin down how many beliefs we have [Williams,M] |
| Full Idea: Asking how many beliefs I have is like asking how many drops of water there are in a bucket. If I believe my dog is in the garden, do I also believe he is not in the house, or in Siberia? | |
| From: Michael Williams (Problems of Knowledge [2001], Ch.11) |
| 3582 | Propositions make error possible, so basic experiential knowledge is impossible [Williams,M] |
| Full Idea: Propositional content is inseparable from possible error. Therefore no judgement, however modest, is indubitable. So if basic experiential knowledge has to be indubitable, there is no such knowledge. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 8) |
| 3592 | Phenomenalism is a form of idealism [Williams,M] |
| Full Idea: Phenomenalism is a form of idealism. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch.12) |
| 3579 | Sense data avoid the danger of misrepresenting the world [Williams,M] |
| Full Idea: The point of insisting on the absolute immediacy of sense data is that representation always seems to involve the possibility of misrepresentation. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 8) |
| 3581 | Sense data can't give us knowledge if they are non-propositional [Williams,M] |
| Full Idea: Acquaintance with sense data is supposed to be a form of non-propositional knowledge, but how can something be non-propositional and yet knowledge? | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 8) |
| 3564 | Is it people who are justified, or propositions? [Williams,M] |
| Full Idea: What exactly is supposed to be 'justified': a person's believing some particular proposition, or the proposition that he believes? | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 1) | |
| A reaction: A key distinction. See my comment on Idea 3752. What would justify a sign saying 'treasure buried here'? People can be justified in believing falsehoods. How could a false proposition be justified? |
| 8851 | Coherentists say that regress problems are assuming 'linear' justification [Williams,M] |
| Full Idea: From the point of view of the coherentist, Agrippa's Dilemma fails because it presupposes a 'linear' conception of justifying inference. | |
| From: Michael Williams (Without Immediate Justification [2005], §2) | |
| A reaction: [He cites Bonjour 1985 for this view] Since a belief may have several justifications, and one belief could justify a host of others, there certainly isn't a simple line of justifications. I agree with the coherentist picture here. |
| 3595 | What works always takes precedence over theories [Williams,M] |
| Full Idea: A theory that represents working practices as unworkable is a bad theory. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch.13) | |
| A reaction: Good point. There's a lot of this about in epistemology, especially accusations of circularity or infinite regress, which (if true) don't somehow seem to worry the cove on the Clapham omnibus. |
| 7450 | In the medieval view, only deduction counted as true evidence [Hacking] |
| Full Idea: In the medieval view, evidence short of deduction was not really evidence at all. | |
| From: Ian Hacking (The Emergence of Probability [1975], Ch.3) | |
| A reaction: Hacking says the modern concept of evidence comes with probability in the 17th century. That might make it one of the most important ideas ever thought of, allowing us to abandon certainties and live our lives in a more questioning way. |
| 7451 | Formerly evidence came from people; the new idea was that things provided evidence [Hacking] |
| Full Idea: In the medieval view, people provided the evidence of testimony and of authority. What was lacking was the seventeenth century idea of the evidence provided by things. | |
| From: Ian Hacking (The Emergence of Probability [1975], Ch.4) | |
| A reaction: A most intriguing distinction, which seems to imply a huge shift in world-view. The culmination of this is Peirce's pragmatism, in Idea 6948, of which I strongly approve. |
| 8849 | Traditional foundationalism is radically internalist [Williams,M] |
| Full Idea: Traditional foundationalism is radically internalist. The justification-making factors for beliefs, basic and otherwise, are all open to view, and perhaps even actual objects of awareness. I am always in a position to know that I know. | |
| From: Michael Williams (Without Immediate Justification [2005], §1) | |
| A reaction: This is a helpful if one is trying to draw a map of the debate. An externalist foundationalism would have to terminate in the external fact which was the object of knowledge (via some reliable channel), but that is the truth, not the justification. |
| 3580 | Experience must be meaningful to act as foundations [Williams,M] |
| Full Idea: If we are to treat experience as the foundation of knowledge, then experience must itself be understood to involve propositional content. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 8) | |
| A reaction: This sounds right, but since pure 'experience' obviously doesn't have propositional content, because it needs interpretation and evaluation, then this strategy won't work. |
| 8853 | Basic judgements are immune from error because they have no content [Williams,M] |
| Full Idea: Basic judgements threaten to buy their immunity from error at the cost of being drained of descriptive content altogether. | |
| From: Michael Williams (Without Immediate Justification [2005], §4) | |
| A reaction: This is probably the key objection to foundationalism. As you import sufficient content into basic experiences to enable them to actually justify a set of beliefs, you find you have imported all sorts of comparisons and classifications as well. |
| 3578 | Are empirical foundations judgements or experiences? [Williams,M] |
| Full Idea: Empirical foundationists must decide whether knowledge ultimately rests on either beliefs or judgements about experience, or on the experiences or sensations themselves. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 8) | |
| A reaction: This clarifies the key issue very nicely, and I firmly vote for the former option. The simplest point is that error is possible about what sensations are taken to be of, so they won't do on their own. |
| 8855 | Sensory experience may be fixed, but it can still be misdescribed [Williams,M] |
| Full Idea: The fact that experiential contents cannot be other than they are, as far as sensory awareness goes, does not imply that we cannot misdescribe them, as in misreporting the number of speckles on a speckled hen (Chisholm's example). | |
| From: Michael Williams (Without Immediate Justification [2005], §4) | |
| A reaction: [Chisholm 1942 is cited] Such experiences couldn't be basic beliefs if there was a conflict between their intrinsic nature and the description I used in discussing them. |
| 3576 | Foundationalists are torn between adequacy and security [Williams,M] |
| Full Idea: The foundationalists dilemma is to define a basis for knowledge modest enough to be secure but rich enough to be adequate. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 7) | |
| A reaction: ..And that is just what they are unable to do, precisely because adequate support would have to have enough content to be defeasibe or fallible. |
| 3577 | Strong justification eliminates error, but also reduces our true beliefs [Williams,M] |
| Full Idea: A strongly justificationist view of rationality may not be so rational; we want the truth, but avoiding all errors and maximising our number of true beliefs are not the same thing. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 7) | |
| A reaction: An interesting dilemma - to avoid all errors, believing nothing; to maximise true belief, believe everything. It is rational to follow intuition, guesses, and a wing and a prayer - once you are experienced and educated. |
| 3589 | Why should diverse parts of our knowledge be connected? [Williams,M] |
| Full Idea: Why should political theory ever have much to do with quantum physics, or pet care with parliamentary history? | |
| From: Michael Williams (Problems of Knowledge [2001], Ch.11) | |
| A reaction: This hardly demolishes the coherence account of justification, since your views on pet care had better be coherent, for your pet's sake. It's a pity people can make their politics cohere with their ethics. |
| 3590 | Coherence theory must give a foundational status to coherence itself [Williams,M] |
| Full Idea: Coherence theory implicitly assigns the criteria of coherence a special status. …In so far as this status is assigned a priori, the coherence theory represents a rationalistic variant of foundationalism. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch.11) | |
| A reaction: Nice move, to accuse coherence theorists of foundationalism! Wrong, though, because the a priori principles of coherence are not basic beliefs, but evolved pragmatic procedures (or something...). |
| 3571 | Externalism does not require knowing that you know [Williams,M] |
| Full Idea: From an externalist point of view, knowing about one's reliability is not required for 'first-order' knowledge. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 2) | |
| A reaction: Ah. 'First-order knowledge' - what's that? What we used to call 'true belief', I would say. Adequate for animals, and a good guide to daily life, but uncritical and unjustifiable. |
| 3574 | Externalism ignores the social aspect of knowledge [Williams,M] |
| Full Idea: A problem with pure externalism is that it ignores the social dimension of knowledge. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 2) | |
| A reaction: This seems to be contradicted by Idea 3573, which allows a social dimension to agreement over what is reliable. I am inclined to take knowledge as an entirely social concept. |
| 3569 | In the causal theory of knowledge the facts must cause the belief [Williams,M] |
| Full Idea: According to Goldman's early causal theory of knowledge, my belief that p counts as knowledge if and only if it is caused by the fact that p. This is sufficient as well as necessary, and so does not involve justification. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 2) | |
| A reaction: I take his theory simply to be false because what causes a belief is not what justifies it. I expect my mother to ring; the phone rings; I 'know' it is my mother (and it is), because I strongly expect it. |
| 3567 | How could there be causal relations to mathematical facts? [Williams,M] |
| Full Idea: It is not clear what would even be meant by supposing that there are causal relations to mathematical facts. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 2) | |
| A reaction: I agree, though platonists seem to be willing to entertain the possibility that there are causal relations, for which no further explanation can be given. Better is knowledge without a causal relation. |
| 3586 | Only a belief can justify a belief [Williams,M] |
| Full Idea: Justification requires logical rather than causal connections. That is the point of the slogan that only a belief can justify a belief. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch.10) | |
| A reaction: It seems better to talk of 'rational' connections, rather than 'logical' connections. It isn't 'logical' to believe that someone despises me because their lip is faintly curled. |
| 3573 | Externalist reliability refers to a range of conventional conditions [Williams,M] |
| Full Idea: The radical externalists' key notion is 'reliability', which is a normative condition governing adequate performance, involving reference to a range of conditions which we decide rather than discover. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 2) | |
| A reaction: If we can decide whether a source is reliable, we can also decide whether a reliable source has performed well on this occasion, and that will always take precedence. |
| 3565 | Sometimes I ought to distrust sources which are actually reliable [Williams,M] |
| Full Idea: I may reach a belief using a procedure that is in fact reliable, but which I ought to distrust. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 1) | |
| A reaction: The tramp on the park bench who gives good share tips. The clock that is finally working, but has been going haywire for weeks. Reliabilism is a bad theory. |
| 3566 | We control our beliefs by virtue of how we enquire [Williams,M] |
| Full Idea: We control our beliefs by virtue of how we enquire. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 1) |
| 8852 | In the context of scepticism, externalism does not seem to be an option [Williams,M] |
| Full Idea: In the peculiar context of the skeptical challenge, it is easy to persuade oneself that externalism is not an option. | |
| From: Michael Williams (Without Immediate Justification [2005], §3) | |
| A reaction: This is because externalism sees justification as largely non-conscious, but when faced with scepticism, the justifications need to be spelled out, and therefore internalised. So are sceptical discussions basic, or freakish anomalies? |
| 3594 | Scepticism just reveals our limited ability to explain things [Williams,M] |
| Full Idea: All the sceptic's arguments show is that there are limits to our capacity to give reasons or cite evidence. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch.13) |
| 3575 | Scepticism can involve discrepancy, relativity, infinity, assumption and circularity [Williams,M] |
| Full Idea: The classical Five Modes of Scepticism are Discrepancy (people always disagree), Relativity ('according to you'), Infinity (infinite regress of questions), Assumption (ending in dogma) and Circularity (end up where you started). | |
| From: Michael Williams (Problems of Knowledge [2001], Ch. 5) | |
| A reaction: I take Relativity to be different from scepticism (because, roughly, it says there is nothing to know), and the others go with Agrippa's Trilemma of justification, which may have solutions. |
| 3587 | Seeing electrons in a cloud chamber requires theory [Williams,M] |
| Full Idea: Armed with enough theory, we can see electrons in a cloud chamber. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch.10) |
| 7452 | An experiment is a test, or an adventure, or a diagnosis, or a dissection [Hacking, by PG] |
| Full Idea: An experiment is a test (if T, then E implies R, so try E, and if R follows, T seems right), an adventure (no theory, but try things), a diagnosis (reading the signs), or a dissection (taking apart). | |
| From: report of Ian Hacking (The Emergence of Probability [1975], Ch.4) by PG - Db (ideas) | |
| A reaction: A nice analysis. The Greeks did diagnosis, then the alchemists tried adventures, then Vesalius began dissections, then the followers of Bacon concentrated on the test, setting up controlled conditions. 'If you don't believe it, try it yourself'. |
| 7459 | Follow maths for necessary truths, and jurisprudence for contingent truths [Hacking] |
| Full Idea: Mathematics is the model for reasoning about necessary truths, but jurisprudence must be our model when we deliberate about contingencies. | |
| From: Ian Hacking (The Emergence of Probability [1975], Ch.10) | |
| A reaction: Interesting. Certainly huge thinking, especially since the Romans, has gone into the law, and creating rules of evidence. Maybe all philosophers should study law and mathematics? |
| 3588 | Foundationalists base meaning in words, coherentists base it in sentences [Williams,M] |
| Full Idea: In the foundationalist picture the meaning of individual words (defined ostensively) is primary, and that of sentences is derivative. For coherentists sentences come first, with meaning understood functionally or inferentially. | |
| From: Michael Williams (Problems of Knowledge [2001], Ch.10) | |
| A reaction: Coherentism about language doesn't imply coherentism about justification. On language I vote for foundationalism, because I am impressed by the phenomenon of compositionality. |