142 ideas
13860 | We can only learn from philosophers of the past if we accept the risk of major misrepresentation [Wright,C] |
24069 | Much metaphysical debate concerns what is fundamental, rather than what exists [Koslicki] |
18835 | Logic doesn't have a metaphysical basis, but nor can logic give rise to the metaphysics [Rumfitt] |
13883 | The best way to understand a philosophical idea is to defend it [Wright,C] |
17311 | Real definitions don't just single out a thing; they must also explain its essence [Koslicki] |
15118 | A successful Aristotelian 'definition' is what sciences produces after an investigation [Koslicki] |
15116 | Essences cause necessary features, and definitions describe those necessary features [Koslicki] |
10142 | The attempt to define numbers by contextual definition has been revived [Wright,C, by Fine,K] |
18819 | The idea that there are unrecognised truths is basic to our concept of truth [Rumfitt] |
18826 | 'True at a possibility' means necessarily true if what is said had obtained [Rumfitt] |
18803 | Semantics for propositions: 1) validity preserves truth 2) non-contradition 3) bivalence 4) truth tables [Rumfitt] |
12204 | The logic of metaphysical necessity is S5 [Rumfitt] |
18814 | 'Absolute necessity' would have to rest on S5 [Rumfitt] |
18798 | It is the second-order part of intuitionistic logic which actually negates some classical theorems [Rumfitt] |
18799 | Intuitionists can accept Double Negation Elimination for decidable propositions [Rumfitt] |
18830 | Most set theorists doubt bivalence for the Continuum Hypothesis, but still use classical logic [Rumfitt] |
18843 | The iterated conception of set requires continual increase in axiom strength [Rumfitt] |
18836 | A set may well not consist of its members; the empty set, for example, is a problem [Rumfitt] |
18837 | A set can be determinate, because of its concept, and still have vague membership [Rumfitt] |
18845 | If the totality of sets is not well-defined, there must be doubt about the Power Set Axiom [Rumfitt] |
13258 | The 'aggregative' objections says mereology gets existence and location of objects wrong [Koslicki] |
18815 | Logic is higher-order laws which can expand the range of any sort of deduction [Rumfitt] |
11211 | If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt] |
9390 | Logic guides thinking, but it isn't a substitute for it [Rumfitt] |
18805 | Classical logic rules cannot be proved, but various lines of attack can be repelled [Rumfitt] |
18804 | The case for classical logic rests on its rules, much more than on the Principle of Bivalence [Rumfitt] |
18827 | If truth-tables specify the connectives, classical logic must rely on Bivalence [Rumfitt] |
13288 | Consequence is truth-preserving, either despite substitutions, or in all interpretations [Koslicki] |
12195 | Soundness in argument varies with context, and may be achieved very informally indeed [Rumfitt] |
12199 | There is a modal element in consequence, in assessing reasoning from suppositions [Rumfitt] |
12201 | We reject deductions by bad consequence, so logical consequence can't be deduction [Rumfitt] |
18813 | Logical consequence is a relation that can extended into further statements [Rumfitt] |
18808 | Normal deduction presupposes the Cut Law [Rumfitt] |
14506 | 'Roses are red; therefore, roses are colored' seems truth-preserving, but not valid in a system [Koslicki] |
18840 | When faced with vague statements, Bivalence is not a compelling principle [Rumfitt] |
12194 | Contradictions include 'This is red and not coloured', as well as the formal 'B and not-B' [Rumfitt] |
11210 | Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt] |
11212 | The sense of a connective comes from primitively obvious rules of inference [Rumfitt] |
18802 | In specifying a logical constant, use of that constant is quite unavoidable [Rumfitt] |
9868 | An expression refers if it is a singular term in some true sentences [Wright,C, by Dummett] |
12198 | Geometrical axioms in logic are nowadays replaced by inference rules (which imply the logical truths) [Rumfitt] |
18800 | Introduction rules give deduction conditions, and Elimination says what can be deduced [Rumfitt] |
18809 | Logical truths are just the assumption-free by-products of logical rules [Rumfitt] |
18807 | Monotonicity means there is a guarantee, rather than mere inductive support [Rumfitt] |
13861 | Number theory aims at the essence of natural numbers, giving their nature, and the epistemology [Wright,C] |
13892 | One could grasp numbers, and name sizes with them, without grasping ordering [Wright,C] |
18842 | Maybe an ordinal is a property of isomorphic well-ordered sets, and not itself a set [Rumfitt] |
17435 | Objects do not naturally form countable units [Koslicki] |
17433 | We can still count squares, even if they overlap [Koslicki] |
17439 | There is no deep reason why we count carrots but not asparagus [Koslicki] |
17462 | A single object must not be counted twice, which needs knowledge of distinctness (negative identity) [Rumfitt] |
13867 | Instances of a non-sortal concept can only be counted relative to a sortal concept [Wright,C] |
17434 | We struggle to count branches and waves because our concepts lack clear boundaries [Koslicki] |
18834 | Infinitesimals do not stand in a determinate order relation to zero [Rumfitt] |
18846 | Cantor and Dedekind aimed to give analysis a foundation in set theory (rather than geometry) [Rumfitt] |
17312 | It is more explanatory if you show how a number is constructed from basic entities and relations [Koslicki] |
17441 | Wright thinks Hume's Principle is more fundamental to cardinals than the Peano Axioms are [Wright,C, by Heck] |
13862 | There are five Peano axioms, which can be expressed informally [Wright,C] |
17853 | Number truths are said to be the consequence of PA - but it needs semantic consequence [Wright,C] |
17854 | What facts underpin the truths of the Peano axioms? [Wright,C] |
13894 | Sameness of number is fundamental, not counting, despite children learning that first [Wright,C] |
17461 | Some 'how many?' answers are not predications of a concept, like 'how many gallons?' [Rumfitt] |
10140 | We derive Hume's Law from Law V, then discard the latter in deriving arithmetic [Wright,C, by Fine,K] |
8692 | Frege has a good system if his 'number principle' replaces his basic law V [Wright,C, by Friend] |
17440 | Wright says Hume's Principle is analytic of cardinal numbers, like a definition [Wright,C, by Heck] |
13893 | It is 1-1 correlation of concepts, and not progression, which distinguishes natural number [Wright,C] |
13888 | If numbers are extensions, Frege must first solve the Caesar problem for extensions [Wright,C] |
14505 | Some questions concern mathematical entities, rather than whole structures [Koslicki] |
13869 | Number platonism says that natural number is a sortal concept [Wright,C] |
13870 | We can't use empiricism to dismiss numbers, if numbers are our main evidence against empiricism [Wright,C] |
13873 | Treating numbers adjectivally is treating them as quantifiers [Wright,C] |
7804 | Wright has revived Frege's discredited logicism [Wright,C, by Benardete,JA] |
13899 | The Peano Axioms, and infinity of cardinal numbers, are logical consequences of how we explain cardinals [Wright,C] |
13896 | The aim is to follow Frege's strategy to derive the Peano Axioms, but without invoking classes [Wright,C] |
13863 | Logicism seemed to fail by Russell's paradox, Gödel's theorems, and non-logical axioms [Wright,C] |
13895 | The standard objections are Russell's Paradox, non-logical axioms, and Gödel's theorems [Wright,C] |
13884 | The idea that 'exist' has multiple senses is not coherent [Wright,C] |
17314 | The relata of grounding are propositions or facts, but for dependence it is objects and their features [Koslicki] |
17436 | We talk of snow as what stays the same, when it is a heap or drift or expanse [Koslicki] |
13877 | Singular terms in true sentences must refer to objects; there is no further question about their existence [Wright,C] |
13289 | Structures have positions, constituent types and number, and some invariable parts [Koslicki] |
14501 | 'Categorical' properties exist in the actual world, and 'hypothetical' properties in other worlds [Koslicki] |
9878 | Contextually defined abstract terms genuinely refer to objects [Wright,C, by Dummett] |
13868 | Sortal concepts cannot require that things don't survive their loss, because of phase sortals [Wright,C] |
14495 | I aim to put the notion of structure or form back into the concepts of part, whole and object [Koslicki] |
13264 | If a whole is just a structure, a dinner party wouldn't need the guests to turn up [Koslicki] |
24065 | Structured wholes are united by the teamwork needed for their capacities [Koslicki] |
14497 | The clay is just a part of the statue (its matter); the rest consists of its form or structure [Koslicki] |
13280 | Statue and clay differ in modal and temporal properties, and in constitution [Koslicki] |
9389 | Vague membership of sets is possible if the set is defined by its concept, not its members [Rumfitt] |
18839 | An object that is not clearly red or orange can still be red-or-orange, which sweeps up problem cases [Rumfitt] |
18838 | The extension of a colour is decided by a concept's place in a network of contraries [Rumfitt] |
24066 | The form explains kind, structure, unity and activity [Koslicki] |
14496 | Structure or form are right at the centre of modern rigorous modes of enquiry [Koslicki] |
13279 | There are at least six versions of constitution being identity [Koslicki] |
14498 | For three-dimensionalist parthood must be a three-place relation, including times [Koslicki] |
13283 | The parts may be the same type as the whole, like a building made of buildings [Koslicki] |
13266 | Wholes in modern mereology are intended to replace sets, so they closely resemble them [Koslicki] |
14500 | Wholes are entities distinct from their parts, and have different properties [Koslicki] |
13281 | Wholes are not just their parts; a whole is an entity distinct from the proper parts [Koslicki] |
15110 | An essence and what merely follow from it are distinct [Koslicki] |
17313 | Modern views want essences just to individuate things across worlds and times [Koslicki] |
15113 | Individuals are perceived, but demonstration and definition require universals [Koslicki] |
24067 | Hylomorphic compounds need an individual form for transworld identity [Koslicki] |
17309 | For Fine, essences are propositions true because of identity, so they are just real definitions [Koslicki] |
17315 | We need a less propositional view of essence, and so must distinguish it clearly from real definitions [Koslicki] |
15112 | If an object exists, then its essential properties are necessary [Koslicki] |
14532 | A distinctive type of necessity is found in logical consequence [Rumfitt, by Hale/Hoffmann,A] |
18816 | Metaphysical modalities respect the actual identities of things [Rumfitt] |
12189 | Logical necessity involves a decision about usage, and is non-realist and non-cognitive [Wright,C, by McFetridge] |
12193 | Logical necessity is when 'necessarily A' implies 'not-A is contradictory' [Rumfitt] |
12200 | A logically necessary statement need not be a priori, as it could be unknowable [Rumfitt] |
12202 | Narrow non-modal logical necessity may be metaphysical, but real logical necessity is not [Rumfitt] |
18825 | S5 is the logic of logical necessity [Rumfitt] |
18824 | Since possibilities are properties of the world, calling 'red' the determination of a determinable seems right [Rumfitt] |
18828 | If two possibilities can't share a determiner, they are incompatible [Rumfitt] |
12203 | If a world is a fully determinate way things could have been, can anyone consider such a thing? [Rumfitt] |
18821 | Possibilities are like possible worlds, but not fully determinate or complete [Rumfitt] |
18831 | Medieval logicians said understanding A also involved understanding not-A [Rumfitt] |
18820 | In English 'evidence' is a mass term, qualified by 'little' and 'more' [Rumfitt] |
15111 | In demonstration, the explanatory order must mirror the causal order of the phenomena [Koslicki] |
15115 | In a demonstration the middle term explains, by being part of the definition [Koslicki] |
17317 | A good explanation captures the real-world dependence among the phenomena [Koslicki] |
15117 | Greek uses the same word for 'cause' and 'explanation' [Koslicki] |
15114 | Discovering the Aristotelian essence of thunder will tell us why thunder occurs [Koslicki] |
13865 | 'Sortal' concepts show kinds, use indefinite articles, and require grasping identities [Wright,C] |
13866 | A concept is only a sortal if it gives genuine identity [Wright,C] |
13890 | Entities fall under a sortal concept if they can be used to explain identity statements concerning them [Wright,C] |
17316 | We can abstract to a dependent entity by blocking out features of its bearer [Koslicki] |
13898 | If we can establish directions from lines and parallelism, we were already committed to directions [Wright,C] |
18817 | We understand conditionals, but disagree over their truth-conditions [Rumfitt] |
13882 | A milder claim is that understanding requires some evidence of that understanding [Wright,C] |
7320 | Holism cannot give a coherent account of scientific methodology [Wright,C, by Miller,A] |
13885 | If apparent reference can mislead, then so can apparent lack of reference [Wright,C] |
17857 | We can accept Frege's idea of object without assuming that predicates have a reference [Wright,C] |
18829 | The truth grounds for 'not A' are the possibilities incompatible with truth grounds for A [Rumfitt] |
11214 | We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt] |
14504 | The Kripke/Putnam approach to natural kind terms seems to give them excessive stability [Koslicki] |
13285 | Natural kinds support inductive inferences, from previous samples to the next one [Koslicki] |
13287 | Concepts for species are either intrinsic structure, or relations like breeding or ancestry [Koslicki] |
13284 | Should vernacular classifications ever be counted as natural kind terms? [Koslicki] |
13286 | There are apparently no scientific laws concerning biological species [Koslicki] |