67 ideas
| 21422 | Moral self-knowledge is the beginning of all human wisdom [Kant] |
| 21408 | For any subject, its system of non-experiential concepts needs a metaphysics [Kant] |
| 18835 | Logic doesn't have a metaphysical basis, but nor can logic give rise to the metaphysics [Rumfitt] |
| 21416 | Philosophers should not offer multiple proofs - suggesting the weakness of each of them [Kant] |
| 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] |
| 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] |
| 21410 | That a concept is not self-contradictory does not make what it represents possible [Kant] |
| 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] |
| 21421 | Within nature man is unimportant, but as moral person he is above any price [Kant] |
| 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] |
| 468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
| 21415 | Duty is impossible without prior moral feeling, conscience, love and self-respect [Kant] |
| 21409 | Moral principles do not involve feelings [Kant] |
| 21431 | The love of man is required in order to present the world as a beautiful and perfect moral whole [Kant] |
| 21437 | All morality directs the will to love of others' ends, and respect for others' rights [Kant] |
| 21429 | The duty of love is to makes the ends of others one's own [Kant] |
| 21411 | A duty of virtue is a duty which is also an end [Kant] |
| 21413 | Virtue is strong maxims for duty [Kant] |
| 21414 | The supreme principle of virtue is to find universal laws for ends [Kant] |
| 21436 | We are obliged to show the social virtues, but at least they make a virtuous disposition fashionable [Kant] |
| 21419 | If virtue becomes a habit, that is a loss of the freedom needed for adopting maxims [Kant] |
| 21417 | How do we distinguish a mean? The extremes can involve quite different maxims [Kant] |
| 21420 | If virtue is the mean between vices, then virtue is just the vanishing of vice [Kant] |
| 21418 | There is one principle of virtues; the virtues are distinguished by their objects [Kant] |
| 21425 | We can love without respect, and show respect without love [Kant] |
| 21427 | Respect is limiting our self-esteem by attending to the human dignity of other persons [Kant] |
| 21430 | Disrespect is using a person as a mere means to my own ends [Kant] |
| 21428 | Respect is purely negative (of not exalting oneself over others), and is thus a duty of Right [Kant] |
| 21426 | Love urges us to get closer to people, but respect to keep our distance [Kant] |
| 21434 | We must respect the humanity even in a vicious criminal [Kant] |
| 21412 | Humans are distinguished from animals by their capacity to set themselves any sort of end [Kant] |
| 21435 | Man is both social, and unsociable [Kant] |
| 21433 | Violation of rights deserves punishment, which is vengeance, rather than restitution [Kant] |
| 21423 | Men can only have duties to those who qualify as persons [Kant] |
| 21424 | Cruelty to animals is bad because it dulls our empathy for pain in humans [Kant] |