60 ideas
3600 | Slow and accurate thought makes the greatest progress [Descartes] |
3601 | Most things in human life seem vain and useless [Descartes] |
3602 | Almost every daft idea has been expressed by some philosopher [Descartes] |
18835 | Logic doesn't have a metaphysical basis, but nor can logic give rise to the metaphysics [Rumfitt] |
3603 | Methodical thinking is cautious, analytical, systematic, and panoramic [Descartes, by PG] |
3612 | Clear and distinct conceptions are true because a perfect God exists [Descartes] |
18819 | The idea that there are unrecognised truths is basic to our concept of truth [Rumfitt] |
3610 | Truth is clear and distinct conception - of which it is hard to be sure [Descartes] |
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] |
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] |
18815 | Logic is higher-order laws which can expand the range of any sort of deduction [Rumfitt] |
18804 | The case for classical logic rests on its rules, much more than on the Principle of Bivalence [Rumfitt] |
18805 | Classical logic rules cannot be proved, but various lines of attack can be repelled [Rumfitt] |
18827 | If truth-tables specify the connectives, classical logic must rely on Bivalence [Rumfitt] |
18813 | Logical consequence is a relation that can extended into further statements [Rumfitt] |
18808 | Normal deduction presupposes the Cut Law [Rumfitt] |
18840 | When faced with vague statements, Bivalence is not a compelling principle [Rumfitt] |
18802 | In specifying a logical constant, use of that constant is quite unavoidable [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] |
18842 | Maybe an ordinal is a property of isomorphic well-ordered sets, and not itself a set [Rumfitt] |
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] |
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] |
18816 | Metaphysical modalities respect the actual identities of things [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] |
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] |
3605 | We can believe a thing without knowing we believe it [Descartes] |
1583 | In morals Descartes accepts the conventional, but rejects it in epistemology [Roochnik on Descartes] |
3607 | In thinking everything else false, my own existence remains totally certain [Descartes] |
3617 | I aim to find the principles and causes of everything, using the seeds within my mind [Descartes] |
3611 | Understanding, rather than imagination or senses, gives knowledge [Descartes] |
18820 | In English 'evidence' is a mass term, qualified by 'little' and 'more' [Rumfitt] |
3606 | I was searching for reliable rock under the shifting sand [Descartes] |
3604 | When rebuilding a house, one needs alternative lodgings [Descartes] |
3618 | Only experiments can settle disagreements between rival explanations [Descartes] |
3615 | Little reason is needed to speak, so animals have no reason at all [Descartes] |
3609 | I am a thinking substance, which doesn't need a place or material support [Descartes] |
3608 | I can deny my body and the world, but not my own existence [Descartes] |
3613 | Reason is universal in its responses, but a physical machine is constrained by its organs [Descartes] |
3616 | The soul must unite with the body to have appetites and sensations [Descartes] |
3614 | A machine could speak in response to physical stimulus, but not hold a conversation [Descartes] |
18817 | We understand conditionals, but disagree over their truth-conditions [Rumfitt] |
18829 | The truth grounds for 'not A' are the possibilities incompatible with truth grounds for A [Rumfitt] |
1581 | Greeks elevate virtues enormously, but never explain them [Descartes] |
7810 | The 'Eumenides' of Aeschylus shows blood feuds replaced by law [Aeschylus, by Grayling] |
16686 | God has established laws throughout nature, and implanted ideas of them within us [Descartes] |