64 ideas
12667 | Metaphysics aims at the simplest explanation, without regard to testability [Ellis] |
21959 | Metaphysics is the most general attempt to make sense of things [Moore,AW] |
18835 | Logic doesn't have a metaphysical basis, but nor can logic give rise to the metaphysics [Rumfitt] |
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] |
12666 | We can base logic on acceptability, and abandon the Fregean account by truth-preservation [Ellis] |
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] |
12688 | Mathematics is the formal study of the categorical dimensions of things [Ellis] |
18846 | Cantor and Dedekind aimed to give analysis a foundation in set theory (rather than geometry) [Rumfitt] |
12683 | Objects and substances are a subcategory of the natural kinds of processes [Ellis] |
12670 | A physical event is any change of distribution of energy [Ellis] |
12673 | Physical properties are those relevant to how a physical system might act [Ellis] |
12665 | I support categorical properties, although most people only want causal powers [Ellis] |
12682 | Essentialism needs categorical properties (spatiotemporal and numerical relations) and dispositions [Ellis] |
12684 | Spatial, temporal and numerical relations have causal roles, without being causal [Ellis] |
12672 | Properties and relations are discovered, so they can't be mere sets of individuals [Ellis] |
12676 | Causal powers can't rest on things which lack causal power [Ellis] |
23781 | Categoricals exist to influence powers. Such as structures, orientations and magnitudes [Ellis, by Williams,NE] |
12686 | Causal powers are a proper subset of the dispositional properties [Ellis] |
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] |
12685 | Categorical properties depend only on the structures they represent [Ellis] |
12679 | A real essence is a kind's distinctive properties [Ellis] |
12668 | Metaphysical necessity holds between things in the world and things they make true [Ellis] |
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] |
12687 | Metaphysical necessities are those depending on the essential nature of things [Ellis] |
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] |
21958 | Appearances are nothing beyond representations, which is transcendental ideality [Moore,AW] |
18820 | In English 'evidence' is a mass term, qualified by 'little' and 'more' [Rumfitt] |
12669 | Science aims to explain things, not just describe them [Ellis] |
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] |
12681 | There are natural kinds of processes [Ellis] |
12680 | Natural kind structures go right down to the bottom level [Ellis] |
12675 | Laws of nature are just descriptions of how things are disposed to behave [Ellis] |
12671 | I deny forces as entities that intervene in causation, but are not themselves causal [Ellis] |
12674 | Energy is the key multi-valued property, vital to scientific realism [Ellis] |
12689 | Simultaneity can be temporal equidistance from the Big Bang [Ellis] |
12690 | The present is the collapse of the light wavefront from the Big Bang [Ellis] |