114 ideas
3879 | Philosophy aims to provide a theory of everything [Scruton] |
3891 | If p entails q, then p is sufficient for q, and q is necessary for p [Scruton] |
18137 | Impredicative definitions are wrong, because they change the set that is being defined? [Bostock] |
3894 | We may define 'good' correctly, but then ask whether the application of the definition is good [Scruton] |
3883 | A true proposition is consistent with every other true proposition [Scruton] |
3884 | The pragmatist does not really have a theory of truth [Scruton] |
18122 | Classical interdefinitions of logical constants and quantifiers is impossible in intuitionism [Bostock] |
18114 | There is no single agreed structure for set theory [Bostock] |
18107 | A 'proper class' cannot be a member of anything [Bostock] |
18115 | We could add axioms to make sets either as small or as large as possible [Bostock] |
18139 | The Axiom of Choice relies on reference to sets that we are unable to describe [Bostock] |
18105 | Replacement enforces a 'limitation of size' test for the existence of sets [Bostock] |
18108 | First-order logic is not decidable: there is no test of whether any formula is valid [Bostock] |
18109 | The completeness of first-order logic implies its compactness [Bostock] |
16357 | Mental files are the counterparts of singular terms [Recanati] |
18123 | Substitutional quantification is just standard if all objects in the domain have a name [Bostock] |
18120 | The Deduction Theorem is what licenses a system of natural deduction [Bostock] |
18125 | Berry's Paradox considers the meaning of 'The least number not named by this name' [Bostock] |
18101 | Each addition changes the ordinality but not the cardinality, prior to aleph-1 [Bostock] |
18100 | ω + 1 is a new ordinal, but its cardinality is unchanged [Bostock] |
18102 | A cardinal is the earliest ordinal that has that number of predecessors [Bostock] |
18106 | Aleph-1 is the first ordinal that exceeds aleph-0 [Bostock] |
18095 | Instead of by cuts or series convergence, real numbers could be defined by axioms [Bostock] |
18099 | The number of reals is the number of subsets of the natural numbers [Bostock] |
18093 | For Eudoxus cuts in rationals are unique, but not every cut makes a real number [Bostock] |
3907 | Could you be intellectually acquainted with numbers, but unable to count objects? [Scruton] |
18110 | Infinitesimals are not actually contradictory, because they can be non-standard real numbers [Bostock] |
18156 | Modern axioms of geometry do not need the real numbers [Bostock] |
18097 | The Peano Axioms describe a unique structure [Bostock] |
18148 | Hume's Principle is a definition with existential claims, and won't explain numbers [Bostock] |
18145 | Many things will satisfy Hume's Principle, so there are many interpretations of it [Bostock] |
18149 | There are many criteria for the identity of numbers [Bostock] |
18143 | Frege makes numbers sets to solve the Caesar problem, but maybe Caesar is a set! [Bostock] |
18116 | Numbers can't be positions, if nothing decides what position a given number has [Bostock] |
18117 | Structuralism falsely assumes relations to other numbers are numbers' only properties [Bostock] |
18141 | Nominalism about mathematics is either reductionist, or fictionalist [Bostock] |
18157 | Nominalism as based on application of numbers is no good, because there are too many applications [Bostock] |
18150 | Actual measurement could never require the precision of the real numbers [Bostock] |
18158 | Ordinals are mainly used adjectively, as in 'the first', 'the second'... [Bostock] |
18127 | Simple type theory has 'levels', but ramified type theory has 'orders' [Bostock] |
18144 | Neo-logicists agree that HP introduces number, but also claim that it suffices for the job [Bostock] |
18147 | Neo-logicists meet the Caesar problem by saying Hume's Principle is unique to number [Bostock] |
18146 | If Hume's Principle is the whole story, that implies structuralism [Bostock] |
18129 | Many crucial logicist definitions are in fact impredicative [Bostock] |
18111 | Treating numbers as objects doesn't seem like logic, since arithmetic fixes their totality [Bostock] |
18159 | Higher cardinalities in sets are just fairy stories [Bostock] |
18155 | A fairy tale may give predictions, but only a true theory can give explanations [Bostock] |
3908 | If maths contains unprovable truths, then maths cannot be reduced to a set of proofs [Scruton] |
18140 | The best version of conceptualism is predicativism [Bostock] |
18138 | Conceptualism fails to grasp mathematical properties, infinity, and objective truth values [Bostock] |
18131 | If abstracta only exist if they are expressible, there can only be denumerably many of them [Bostock] |
18134 | Predicativism makes theories of huge cardinals impossible [Bostock] |
18135 | If mathematics rests on science, predicativism may be the best approach [Bostock] |
18136 | If we can only think of what we can describe, predicativism may be implied [Bostock] |
18132 | The predicativity restriction makes a difference with the real numbers [Bostock] |
18133 | The usual definitions of identity and of natural numbers are impredicative [Bostock] |
3906 | If possible worlds are needed to define properties, maybe we should abandon properties [Scruton] |
16360 | Identity statements are informative if they link separate mental files [Recanati] |
3888 | Hume assumes that necessity can only be de dicto, not de re [Scruton] |
3903 | The conceivable can't be a test of the possible, if there are things which are possible but inconceivable [Scruton] |
3897 | Epistemology is about the justification of belief, not the definition of knowledge [Scruton] |
3881 | In the Cogito argument consciousness develops into self-consciousness [Scruton] |
16374 | There is a continuum from acquaintance to description in knowledge, depending on the link [Recanati] |
3887 | Maybe our knowledge of truth and causation is synthetic a priori [Scruton] |
3901 | Touch only seems to reveal primary qualities [Scruton] |
3885 | We only conceive of primary qualities as attached to secondary qualities [Scruton] |
3910 | If primary and secondary qualities are distinct, what has the secondary qualities? [Scruton] |
3899 | The representational theory says perceptual states are intentional states [Scruton] |
3898 | My belief that it will rain tomorrow can't be caused by its raining tomorrow [Scruton] |
3880 | Logical positivism avoids scepticism, by closing the gap between evidence and conclusion [Scruton] |
3878 | Why should you believe someone who says there are no truths? [Scruton] |
3892 | Every event having a cause, and every event being determined by its cause, are not the same [Scruton] |
3911 | The very concept of a substance denies the possibility of mutual interaction and dependence [Scruton] |
18409 | Indexicals apply to singular thought, and mental files have essentially indexical features [Recanati] |
16354 | Indexicality is closely related to singularity, exploiting our direct relations with things [Recanati] |
16371 | Files can be confused, if two files correctly have a single name, or one file has two names [Recanati] |
16373 | Encylopedic files have further epistemic links, beyond the basic one [Recanati] |
16375 | Singular thoughts need a mental file, and an acquaintance relation from file to object [Recanati] |
16377 | Expected acquaintance can create a thought-vehicle file, but without singular content [Recanati] |
16378 | An 'indexed' file marks a file which simulates the mental file of some other person [Recanati] |
16387 | Reference by mental files is Millian, in emphasising acquaintance, rather than satisfaction [Recanati] |
16358 | The reference of a file is fixed by what it relates to, not the information it contains [Recanati] |
16361 | A mental file treats all of its contents as concerning one object [Recanati] |
16367 | There are transient 'demonstrative' files, habitual 'recognitional' files, cumulative 'encyclopedic' files [Recanati] |
16368 | Files are hierarchical: proto-files, then first-order, then higher-order encyclopedic [Recanati] |
16370 | A file has a 'nucleus' through its relation to the object, and a 'periphery' of links to other files [Recanati] |
16381 | The content of thought is what is required to understand it (which involves hearers) [Recanati] |
16365 | Mental files are individual concepts (thought constituents) [Recanati] |
16356 | There may be two types of reference in language and thought: descriptive and direct [Recanati] |
16393 | In super-direct reference, the referent serves as its own vehicle of reference [Recanati] |
16386 | Direct reference is strong Millian (just a tag) or weak Kaplanian (allowing descriptions as well) [Recanati] |
16372 | Sense determines reference says same sense/same reference; new reference means new sense [Recanati] |
16388 | We need sense as well as reference, but in a non-descriptive form, and mental files do that [Recanati] |
16359 | Sense is a mental file (not its contents); similar files for Cicero and Tully are two senses [Recanati] |
16355 | Problems with descriptivism are reference by perception, by communications and by indexicals [Recanati] |
16348 | Descriptivism says we mentally relate to objects through their properties [Recanati] |
16384 | Definite descriptions reveal either a predicate (attributive use) or the file it belongs in (referential) [Recanati] |
16352 | A rigid definite description can be attributive, not referential: 'the actual F, whoever he is….' [Recanati] |
16353 | Singularity cannot be described, and it needs actual world relations [Recanati] |
16382 | Fregean modes of presentation can be understood as mental files [Recanati] |
16389 | If two people think 'I am tired', they think the same thing, and they think different things [Recanati] |
16363 | Indexicals (like mental files) determine their reference relationally, not by satisfaction [Recanati] |
16364 | Indexical don't refer; only their tokens do [Recanati] |
16351 | In 2-D semantics, reference is determined, then singularity by the truth of a predication [Recanati] |
16350 | Two-D semantics is said to help descriptivism of reference deal with singular objects [Recanati] |
16380 | Russellian propositions are better than Fregean thoughts, by being constant through communication [Recanati] |
18121 | In logic a proposition means the same when it is and when it is not asserted [Bostock] |
3882 | Wittgenstein makes it impossible to build foundations from something that is totally private [Scruton] |
3896 | Any social theory of morality has the problem of the 'free rider', who only pretends to join in [Scruton] |
3886 | Membership is the greatest source of obligation [Scruton] |
3895 | The categorical imperative is not just individual, but can be used for negotiations between strangers [Scruton] |
3890 | 'Cause' used to just mean any valid explanation [Scruton] |
3904 | Measuring space requires no movement while I do it [Scruton] |
3905 | 'Existence' is not a predicate of 'man', but of the concept of man, saying it has at least one instance [Scruton] |