41 ideas
| 3099 | Inference is never a conscious process [Harman] |
| Full Idea: Inference is never a conscious process. | |
| From: Gilbert Harman (Thought [1973], 11.2) |
| 3077 | Reasoning might be defined in terms of its functional role, which is to produce knowledge [Harman] |
| Full Idea: Reasoning could be treated as a functionally defined process that is partly defined in terms of its role in giving a person knowledge. | |
| From: Gilbert Harman (Thought [1973], 3.6) |
| 3092 | If you believe that some of your beliefs are false, then at least one of your beliefs IS false [Harman] |
| Full Idea: If a rational man believes he has at least some other false beliefs, it follows that a rational man knows that at least one of his beliefs is false (the one believed false, or this new belief). | |
| From: Gilbert Harman (Thought [1973], 7.2) |
| 10807 | Mathematics reduces to set theory, which reduces, with some mereology, to the singleton function [Lewis] |
| Full Idea: It is generally accepted that mathematics reduces to set theory, and I argue that set theory in turn reduces, with some aid of mereology, to the theory of the singleton function. | |
| From: David Lewis (Mathematics is Megethology [1993], p.03) |
| 10809 | We can accept the null set, but not a null class, a class lacking members [Lewis] |
| Full Idea: In my usage of 'class', there is no such things as the null class. I don't mind calling some memberless thing - some individual - the null set. But that doesn't make it a memberless class. Rather, that makes it a 'set' that is not a class. | |
| From: David Lewis (Mathematics is Megethology [1993], p.05) | |
| A reaction: Lewis calls this usage 'idiosyncratic', but it strikes me as excellent. Set theorists can have their vital null class, and sensible people can be left to say, with Lewis, that classes of things must have members. |
| 10811 | The null set plays the role of last resort, for class abstracts and for existence [Lewis] |
| Full Idea: The null set serves two useful purposes. It is a denotation of last resort for class abstracts that denote no nonempty class. And it is an individual of last resort: we can count on its existence, and fearlessly build the hierarchy of sets from it. | |
| From: David Lewis (Mathematics is Megethology [1993], p.09) | |
| A reaction: This passage assuages my major reservation about the existence of the null set, but at the expense of confirming that it must be taken as an entirely fictional entity. |
| 10812 | The null set is not a little speck of sheer nothingness, a black hole in Reality [Lewis] |
| Full Idea: Should we accept the null set as a most extraordinary individual, a little speck of sheer nothingness, a sort of black hole in the fabric of Reality itself? Not that either, I think. | |
| From: David Lewis (Mathematics is Megethology [1993], p.09) | |
| A reaction: Correct! |
| 10813 | What on earth is the relationship between a singleton and an element? [Lewis] |
| Full Idea: A new student of set theory has just one thing, the element, and he has another single thing, the singleton, and not the slightest guidance about what one thing has to do with the other. | |
| From: David Lewis (Mathematics is Megethology [1993], p.12) |
| 10814 | Are all singletons exact intrinsic duplicates? [Lewis] |
| Full Idea: Are all singletons exact intrinsic duplicates? | |
| From: David Lewis (Mathematics is Megethology [1993], p.13) |
| 10806 | Megethology is the result of adding plural quantification to mereology [Lewis] |
| Full Idea: Megethology is the result of adding plural quantification, as advocated by George Boolos, to the language of mereology. | |
| From: David Lewis (Mathematics is Megethology [1993], p.03) |
| 3093 | Any two states are logically linked, by being entailed by their conjunction [Harman] |
| Full Idea: Any two states of affairs are logically connected, simply because both are entailed by their conjunction. | |
| From: Gilbert Harman (Thought [1973], 8.1) |
| 3098 | Deductive logic is the only logic there is [Harman] |
| Full Idea: Deductive logic is the only logic there is. | |
| From: Gilbert Harman (Thought [1973], 10.4) |
| 3094 | You don't have to accept the conclusion of a valid argument [Harman] |
| Full Idea: We may say "From P and If-P-then-Q, infer Q" (modus ponens), but there is no rule of acceptance to say that we should accept Q. Maybe we should stop believing P or If-P-then-Q rather than believe Q. | |
| From: Gilbert Harman (Thought [1973], 10.1) |
| 3084 | Our underlying predicates represent words in the language, not universal concepts [Harman] |
| Full Idea: The underlying truth-conditional structures of thoughts are language-dependent in the sense that underlying predicates represent words in the language rather than universal concepts common to all languages. | |
| From: Gilbert Harman (Thought [1973], 6.3) |
| 3080 | Logical form is the part of a sentence structure which involves logical elements [Harman] |
| Full Idea: The logical form of a sentence is that part of its structure that involves logical elements. | |
| From: Gilbert Harman (Thought [1973], 5.2) |
| 3081 | A theory of truth in a language must involve a theory of logical form [Harman] |
| Full Idea: Some sort of theory of logical form is involved in any theory of truth for a natural language. | |
| From: Gilbert Harman (Thought [1973], 5.2) |
| 10816 | We can use mereology to simulate quantification over relations [Lewis] |
| Full Idea: We can simulate quantification over relations using megethology. Roughly, a quantifier over relations is a plural quantifier over things that encode ordered pairs by mereological means. | |
| From: David Lewis (Mathematics is Megethology [1993], p.18) | |
| A reaction: [He credits this idea to Burgess and Haven] The point is to avoid second-order logic, which quantifies over relations as ordered n-tuple sets. |
| 10808 | Mathematics is generalisations about singleton functions [Lewis] |
| Full Idea: We can take the theory of singleton functions, and hence set theory, and hence mathematics, to consist of generalisations about all singleton functions. | |
| From: David Lewis (Mathematics is Megethology [1993], p.03) | |
| A reaction: At first glance this sounds like a fancy version of the somewhat discredited Greek idea that mathematics is built on the concept of a 'unit'. |
| 10815 | We don't need 'abstract structures' to have structural truths about successor functions [Lewis] |
| Full Idea: We needn't believe in 'abstract structures' to have general structural truths about all successor functions. | |
| From: David Lewis (Mathematics is Megethology [1993], p.16) |
| 10810 | I say that absolutely any things can have a mereological fusion [Lewis] |
| Full Idea: I accept the principle of Unrestricted Composition: whenever there are some things, no matter how many or how unrelated or how disparate in character they may be, they have a mereological fusion. ...The trout-turkey is part fish and part fowl. | |
| From: David Lewis (Mathematics is Megethology [1993], p.07) | |
| A reaction: This nicely ducks the question of when things form natural wholes and when they don't, but I would have thought that that might be one of the central issues of metaphysicals, so I think I'll give Lewis's principle a miss. |
| 3100 | You have to reaffirm all your beliefs when you make a logical inference [Harman] |
| Full Idea: Since inference is inference to the best total account, all your prior beliefs are relevant and your conclusion is everything you believe at the end. So, you constantly reaffirm your beliefs in inference. | |
| From: Gilbert Harman (Thought [1973], 12.1) |
| 3089 | Only lack of imagination makes us think that 'cats are animals' is analytic [Harman] |
| Full Idea: That 'cats are animals' is often cited as an analytic truth. But (as Putnam points out) the inability to imagine this false is just a lack of imagination. They might turn out to be radio-controlled plastic spies from Mars. | |
| From: Gilbert Harman (Thought [1973], 6.7) |
| 3088 | Analyticity is postulated because we can't imagine some things being true, but we may just lack imagination [Harman] |
| Full Idea: Analyticity is postulated to explain why we cannot imagine certain things being true. A better postulate is that we are not good at imagining things. | |
| From: Gilbert Harman (Thought [1973], 6.7) |
| 3101 | Memories are not just preserved, they are constantly reinferred [Harman] |
| Full Idea: I favour the inferential view of memory over the preservation view. …One constantly reinfers old beliefs. | |
| From: Gilbert Harman (Thought [1973], 12.1) | |
| A reaction: This has a grain of truth, but seems a distortion. An image of the old home floats into my mind when I am thinking about something utterly unconnected. When we search memory we may be inferring and explaining, but the same applies to searching images. |
| 3074 | People's reasons for belief are rarely conscious [Harman] |
| Full Idea: The reasons for which people believe things are rarely conscious. | |
| From: Gilbert Harman (Thought [1973], 2.2) | |
| A reaction: Probably correct. The interesting bit is when they bring the beliefs into consciousness and scrutinise them rationally. Philosophers routinely overthrow their natural beliefs in this way. |
| 3097 | We don't distinguish between accepting, and accepting as evidence [Harman] |
| Full Idea: There is no distinction between what we accept as evidence and whatever else we accept. | |
| From: Gilbert Harman (Thought [1973], 10.4) |
| 6369 | In negative coherence theories, beliefs are prima facie justified, and don't need initial reasons [Harman, by Pollock/Cruz] |
| Full Idea: According to Harman's negative coherence theory it is always permissible to adopt a new belief - any new belief; because beliefs are prima facie justified you do not need a reason for adopting a new belief. | |
| From: report of Gilbert Harman (Thought [1973]) by J Pollock / J Cruz - Contemporary theories of Knowledge (2nd) §3.4.1 | |
| A reaction: This must be placed alongside the fact that we don't usually choose our beliefs, but simply find ourselves believing because of the causal impact of evidence. This gives an unstated rational justification for any belief - something caused it. |
| 3096 | Coherence avoids scepticism, because it doesn't rely on unprovable foundations [Harman] |
| Full Idea: Scepticism is undermined once it is seen that the relevant kind of justification is not a matter of derivation from basic principles but is rather a matter of showing that a view fits in well with other things we believe. | |
| From: Gilbert Harman (Thought [1973], 10.4) | |
| A reaction: I would (now) call myself a 'coherentist' about justification, and I agree with this. Coherent justification could not possibly deliver certainty, so it must be combined with fallibilism. |
| 3095 | Induction is an attempt to increase the coherence of our explanations [Harman] |
| Full Idea: Induction is an attempt to increase the explanatory coherence of our view, making it more complete, less ad hoc, more plausible. | |
| From: Gilbert Harman (Thought [1973], 10.2) |
| 3073 | We see ourselves in the world as a map [Harman] |
| Full Idea: Our conception of ourselves in the world is more like a map than a story. | |
| From: Gilbert Harman (Thought [1973], Pref) | |
| A reaction: Dennett offer the 'story' view of the self (Ideas 7381 and 7382). How do we arbitrate this one? A story IS a sort of map. Maps can extend over time as well over space. I think the self is real, and is a location on a map, and the hero of a story. |
| 3076 | Defining dispositions is circular [Harman] |
| Full Idea: There is no noncircular way to specify dispositions; for they are dispositions to behave given certain situations, and the situations must be include beliefs about the situation, and desires concerning it. | |
| From: Gilbert Harman (Thought [1973], 3.3) | |
| A reaction: This is nowadays accepted dogmatically as the biggest objection to behaviourism, but it could be challenged. Your analysis may begin by mentioning beliefs and desires, but if you keep going they may eventually fade out of the picture. |
| 3075 | Could a cloud have a headache if its particles formed into the right pattern? [Harman] |
| Full Idea: If the right pattern of electrical discharges occurred in a cloud instead of in a brain, would that also be a headache? | |
| From: Gilbert Harman (Thought [1973], 3.2) | |
| A reaction: The standard objection to functionalism is to propose absurd implementations of a mind, but probably only a brain could produce the right electro-chemical combination. |
| 3086 | Are there any meanings apart from in a language? [Harman] |
| Full Idea: The theory of language-independent meanings or semantic representations is mistaken. | |
| From: Gilbert Harman (Thought [1973], 6.5) | |
| A reaction: This would make him (in Dummett's terms) a 'philosopher of language' rather than a 'philosopher of thought'. Personally I disagree. Don't animals have 'meanings'? Can two sentences share a meaning? |
| 3078 | Speech acts, communication, representation and truth form a single theory [Harman] |
| Full Idea: The various theories are not in competition. The theory of truth is part of the theory of representational character, which is presupposed by the theory of communication, which in turn is contained in the more general theory of speech acts. | |
| From: Gilbert Harman (Thought [1973], 4.3) | |
| A reaction: Certainly it seems that the supposed major contenders for a theory of meaning are just as much complements as they are competitors. |
| 3090 | There is only similarity in meaning, never sameness in meaning [Harman] |
| Full Idea: The only sort of sameness of meaning we know is similarity in meaning, not exact sameness of meaning. | |
| From: Gilbert Harman (Thought [1973], 6.8) | |
| A reaction: The Eiffel Tower and le tour Eiffel? If you want to be difficult, you can doubt whether the word 'fast' ever has exactly the same meaning in two separate usages of the word. |
| 3082 | Ambiguity is when different underlying truth-conditional structures have the same surface form [Harman] |
| Full Idea: Ambiguity results from the possibility of transforming different underlying truth-conditional structures into the same surface form. | |
| From: Gilbert Harman (Thought [1973], 5.3) | |
| A reaction: Personally I would call a 'truth-conditional structure' a 'proposition', and leave it to the philosophers to decide what a proposition is. |
| 3079 | Truth in a language is explained by how the structural elements of a sentence contribute to its truth conditions [Harman] |
| Full Idea: A theory of truth for a language shows how the truth conditions of any sentence depend on the structure of that sentence. The theory will say, for each element of structure, what its contribution is. | |
| From: Gilbert Harman (Thought [1973], 5.1) | |
| A reaction: This just seems to push the problem of truth back a stage, as you need to know where the truth is to be found in the elements from which the structure is built. |
| 3085 | Sentences are different from propositions, since two sentences can express one proposition [Harman] |
| Full Idea: 'Bob and John play golf' and 'John and Bob play golf' are equivalent; but if they were to be derived from the same underlying structure, one or the other of Bob and John would have to come first; and either possibility is arbitrary. | |
| From: Gilbert Harman (Thought [1973], 6.4) | |
| A reaction: If I watch Bob and John play golf, neither of them 'comes first'. A proposition about them need not involve 'coming first'. Only if you insist on formulating a sentence must you decide on that. |
| 3087 | The analytic/synthetic distinction is a silly division of thought into encyclopaedia and dictionary [Harman] |
| Full Idea: No purpose is served by thinking that certain principles available to a person are contained in his internal encyclopaedia - and therefore only synthetic - whereas other principles are part of his internal dictionary - and are therefore analytic. | |
| From: Gilbert Harman (Thought [1973], 6.5) | |
| A reaction: If it led to two different ways to acquire knowledge, then quite a lot of purpose would be served. He speaks like a pragmatist. The question is whether some statements just are true because of some feature of meaning. Why not? |
| 3083 | Many predicates totally resist translation, so a universal underlying structure to languages is unlikely [Harman] |
| Full Idea: There are many predicates of a given language that resist translation into another language, …so it is unlikely that there is a basic set of underlying structures common to all languages. | |
| From: Gilbert Harman (Thought [1973], 5.4) | |
| A reaction: Not convincing. 'Structures' are not the same as 'predicates'. Once a language has mapped its predicates, that blocks the intrusions of differently sliced alien predicates. No gaps. |
| 22489 | 'Good' is an attributive adjective like 'large', not predicative like 'red' [Geach, by Foot] |
| Full Idea: Geach puts 'good' in the class of attributive adjectives, such as 'large' and 'small', contrasting such adjectives with 'predicative' adjectives such as 'red'. | |
| From: report of Peter Geach (Good and Evil [1956]) by Philippa Foot - Natural Goodness Intro | |
| A reaction: [In Analysis 17, and 'Theories of Ethics' ed Foot] Thus any object can simply be red, but something can only be large or small 'for a rat' or 'for a car'. Hence nothing is just good, but always a good so-and-so. This is Aristotelian, and Foot loves it. |