81 ideas
4697 | There has been a distinct 'Social Turn' in recent philosophy, like the earlier 'Linguistic Turn' [O'Grady] |
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] |
4731 | Good reasoning will avoid contradiction, enhance coherence, not ignore evidence, and maximise evidence [O'Grady] |
3894 | We may define 'good' correctly, but then ask whether the application of the definition is good [Scruton] |
4735 | Just as maps must simplify their subject matter, so thought has to be reductionist about reality [O'Grady] |
4703 | The epistemic theory of truth presents it as 'that which is licensed by our best theory of reality' [O'Grady] |
3883 | A true proposition is consistent with every other true proposition [Scruton] |
4701 | To say a relative truth is inexpressible in other frameworks is 'weak', while saying it is false is 'strong' [O'Grady] |
3884 | The pragmatist does not really have a theory of truth [Scruton] |
15413 | With four tense operators, all complex tenses reduce to fourteen basic cases [Burgess] |
15415 | The temporal Barcan formulas fix what exists, which seems absurd [Burgess] |
15430 | Is classical logic a part of intuitionist logic, or vice versa? [Burgess] |
15431 | It is still unsettled whether standard intuitionist logic is complete [Burgess] |
15429 | Relevance logic's → is perhaps expressible by 'if A, then B, for that reason' [Burgess] |
15404 | Technical people see logic as any formal system that can be studied, not a study of argument validity [Burgess] |
4705 | Logical relativism appears if we allow more than one legitimate logical system [O'Grady] |
15405 | Classical logic neglects the non-mathematical, such as temporality or modality [Burgess] |
15427 | The Cut Rule expresses the classical idea that entailment is transitive [Burgess] |
15421 | Classical logic neglects counterfactuals, temporality and modality, because maths doesn't use them [Burgess] |
15403 | Philosophical logic is a branch of logic, and is now centred in computer science [Burgess] |
4700 | A third value for truth might be "indeterminate", or a point on a scale between 'true' and 'false' [O'Grady] |
15407 | Formalising arguments favours lots of connectives; proving things favours having very few [Burgess] |
4704 | Wittgenstein reduced Russell's five primitive logical symbols to a mere one [O'Grady] |
15424 | Asserting a disjunction from one disjunct seems odd, but can be sensible, and needed in maths [Burgess] |
15409 | All occurrences of variables in atomic formulas are free [Burgess] |
15414 | The denotation of a definite description is flexible, rather than rigid [Burgess] |
15406 | 'Induction' and 'recursion' on complexity prove by connecting a formula to its atomic components [Burgess] |
15425 | The sequent calculus makes it possible to have proof without transitivity of entailment [Burgess] |
15426 | We can build one expanding sequence, instead of a chain of deductions [Burgess] |
15408 | 'Tautologies' are valid formulas of classical sentential logic - or substitution instances in other logics [Burgess] |
15418 | Validity (for truth) and demonstrability (for proof) have correlates in satisfiability and consistency [Burgess] |
15412 | Models leave out meaning, and just focus on truth values [Burgess] |
15411 | We only need to study mathematical models, since all other models are isomorphic to these [Burgess] |
15416 | We aim to get the technical notion of truth in all models matching intuitive truth in all instances [Burgess] |
15428 | The Liar seems like a truth-value 'gap', but dialethists see it as a 'glut' [Burgess] |
3907 | Could you be intellectually acquainted with numbers, but unable to count objects? [Scruton] |
3908 | If maths contains unprovable truths, then maths cannot be reduced to a set of proofs [Scruton] |
4711 | Anti-realists say our theories (such as wave-particle duality) give reality incompatible properties [O'Grady] |
4698 | What counts as a fact partly depends on the availability of human concepts to describe them [O'Grady] |
3906 | If possible worlds are needed to define properties, maybe we should abandon properties [Scruton] |
4715 | We may say that objects have intrinsic identity conditions, but still allow multiple accounts of them [O'Grady] |
15420 | De re modality seems to apply to objects a concept intended for sentences [Burgess] |
15419 | General consensus is S5 for logical modality of validity, and S4 for proof [Burgess] |
15417 | Logical necessity has two sides - validity and demonstrability - which coincide in classical logic [Burgess] |
3888 | Hume assumes that necessity can only be de dicto, not de re [Scruton] |
15423 | It is doubtful whether the negation of a conditional has any clear meaning [Burgess] |
15422 | Three conditionals theories: Materialism (material conditional), Idealism (true=assertable), Nihilism (no truth) [Burgess] |
4719 | Maybe developments in logic and geometry have shown that the a priori may be relative [O'Grady] |
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] |
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] |
4720 | Sense-data are only safe from scepticism if they are primitive and unconceptualised [O'Grady] |
4722 | Modern epistemology centres on debates about foundations, and about external justification [O'Grady] |
4724 | Internalists say the reasons for belief must be available to the subject, and externalists deny this [O'Grady] |
4723 | Coherence involves support from explanation and evidence, and also probability and confirmation [O'Grady] |
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] |
4709 | Ontological relativists are anti-realists, who deny that our theories carve nature at the joints [O'Grady] |
4725 | Contextualism says that knowledge is relative to its context; 'empty' depends on your interests [O'Grady] |
3878 | Why should you believe someone who says there are no truths? [Scruton] |
4732 | One may understand a realm of ideas, but be unable to judge their rationality or truth [O'Grady] |
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] |
4710 | Verificationism was attacked by the deniers of the analytic-synthetic distinction, needed for 'facts' [O'Grady] |
4717 | If we abandon the analytic-synthetic distinction, scepticism about meaning may be inevitable [O'Grady] |
3882 | Wittgenstein makes it impossible to build foundations from something that is totally private [Scruton] |
4706 | Early Quine says all beliefs could be otherwise, but later he said we would assume mistranslation [O'Grady] |
4734 | Cryptographers can recognise that something is a language, without translating it [O'Grady] |
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] |
4727 | The chief problem for fideists is other fideists who hold contrary ideas [O'Grady] |