65 ideas
| 18835 | Logic doesn't have a metaphysical basis, but nor can logic give rise to the metaphysics [Rumfitt] |
| 23250 | Desired responsible actions result either from rational or from irrational desire [Aristotle] |
| 5847 | It is the role of dialectic to survey syllogisms [Aristotle] |
| 18819 | The idea that there are unrecognised truths is basic to our concept of truth [Rumfitt] |
| 23825 | We seek truth only because it is good [Weil] |
| 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] |
| 18820 | In English 'evidence' is a mass term, qualified by 'little' and 'more' [Rumfitt] |
| 5862 | A single counterexample is enough to prove that a truth is not necessary [Aristotle] |
| 5854 | Nobody fears a disease which nobody has yet caught [Aristotle] |
| 18817 | We understand conditionals, but disagree over their truth-conditions [Rumfitt] |
| 5849 | Rhetoric is a political offshoot of dialectic and ethics [Aristotle] |
| 18829 | The truth grounds for 'not A' are the possibilities incompatible with truth grounds for A [Rumfitt] |
| 5851 | Pentathletes look the most beautiful, because they combine speed and strength [Aristotle] |
| 23826 | Beauty, goodness and truth are only achieved by applying full attention [Weil] |
| 5858 | Men are physically prime at thirty-five, and mentally prime at forty-nine [Aristotle] |
| 5855 | We all feel universal right and wrong, independent of any community or contracts [Aristotle] |
| 23808 | There are two goods - the absolute good we want, and the reachable opposite of evil [Weil] |
| 23833 | The good is a nothingness, and yet real [Weil] |
| 5850 | Happiness is composed of a catalogue of internal and external benefits [Aristotle] |
| 5856 | Self-interest is a relative good, but nobility an absolute good [Aristotle] |
| 5853 | The best virtues are the most useful to others [Aristotle] |
| 5848 | All good things can be misused, except virtue [Aristotle] |
| 5857 | The young feel pity from philanthropy, but the old from self-concern [Aristotle] |
| 5859 | Rich people are mindlessly happy [Aristotle] |
| 5852 | The four constitutions are democracy (freedom), oligarchy (wealth), aristocracy (custom), tyranny (security) [Aristotle] |
| 23831 | The essence of power is illusory prestige [Weil] |
| 23830 | A group is only dangerous if it endorses an abstract entity [Weil] |
| 23809 | Our only social duty is to try to limit evil [Weil] |
| 23807 | The collective is the one and only object of false idolatry [Weil] |
| 23810 | Charity is the only love, and you can feel that for a country (a place with traditions), but not a nation [Weil] |
| 23811 | If effort is from necessity rather than for a good, it is slavery [Weil] |
| 1660 | It is noble to avenge oneself on one's enemies, and not come to terms with them [Aristotle] |
| 5861 | People assume events cause what follows them [Aristotle] |
| 23765 | The soul is the intrinsic value of a human [Weil] |