47 ideas
| 2098 | The principle of sufficient reason is needed if we are to proceed from maths to physics [Leibniz] |
| 3646 | There is always a reason why things are thus rather than otherwise [Leibniz] |
| 2104 | No reason could limit the quantity of matter, so there is no limit [Leibniz] |
| 14018 | Is Sufficient Reason self-refuting (no reason to accept it!), or is it a legitimate explanatory tool? [Bourne] |
| 14008 | The redundancy theory conflates metalinguistic bivalence with object-language excluded middle [Bourne] |
| 10888 | Sets can be defined by 'enumeration', or by 'abstraction' (based on a property) [Zalabardo] |
| 10889 | The 'Cartesian Product' of two sets relates them by pairing every element with every element [Zalabardo] |
| 10890 | A 'partial ordering' is reflexive, antisymmetric and transitive [Zalabardo] |
| 10886 | Determinacy: an object is either in a set, or it isn't [Zalabardo] |
| 10887 | Specification: Determinate totals of objects always make a set [Zalabardo] |
| 10897 | A first-order 'sentence' is a formula with no free variables [Zalabardo] |
| 10893 | Γ |= φ for sentences if φ is true when all of Γ is true [Zalabardo] |
| 10899 | Γ |= φ if φ is true when all of Γ is true, for all structures and interpretations [Zalabardo] |
| 10896 | Propositional logic just needs ¬, and one of ∧, ∨ and → [Zalabardo] |
| 10898 | The semantics shows how truth values depend on instantiations of properties and relations [Zalabardo] |
| 10902 | We can do semantics by looking at given propositions, or by building new ones [Zalabardo] |
| 10892 | We make a truth assignment to T and F, which may be true and false, but merely differ from one another [Zalabardo] |
| 10895 | 'Logically true' (|= φ) is true for every truth-assignment [Zalabardo] |
| 10900 | Logically true sentences are true in all structures [Zalabardo] |
| 10894 | A sentence-set is 'satisfiable' if at least one truth-assignment makes them all true [Zalabardo] |
| 10901 | Some formulas are 'satisfiable' if there is a structure and interpretation that makes them true [Zalabardo] |
| 10903 | A structure models a sentence if it is true in the model, and a set of sentences if they are all true in the model [Zalabardo] |
| 10891 | If a set is defined by induction, then proof by induction can be applied to it [Zalabardo] |
| 19385 | All simply substances are in harmony, because they all represent the one universe [Leibniz] |
| 21346 | The ratio between two lines can't be a feature of one, and cannot be in both [Leibniz] |
| 14010 | All relations between spatio-temporal objects are either spatio-temporal, or causal [Bourne] |
| 14009 | It is a necessary condition for the existence of relations that both of the relata exist [Bourne] |
| 2105 | Things are infinitely subdivisible and contain new worlds, which atoms would make impossible [Leibniz] |
| 2106 | The only simple things are monads, with no parts or extension [Leibniz] |
| 2102 | Atomism is irrational because it suggests that two atoms can be indistinguishable [Leibniz] |
| 20965 | Leibniz upheld conservations of momentum and energy [Leibniz, by Papineau] |
| 14016 | The idea of simultaneity in Special Relativity is full of verificationist assumptions [Bourne] |
| 14019 | Relativity denies simultaneity, so it needs past, present and future (unlike Presentism) [Bourne] |
| 2103 | The idea that the universe could be moved forward with no other change is just a fantasy [Leibniz] |
| 14013 | Special Relativity allows an absolute past, future, elsewhere and simultaneity [Bourne] |
| 2100 | Space and time are purely relative [Leibniz] |
| 14015 | No-Futurists believe in past and present, but not future, and say the world grows as facts increase [Bourne] |
| 14007 | How can presentists talk of 'earlier than', and distinguish past from future? [Bourne] |
| 14011 | Presentism seems to deny causation, because the cause and the effect can never coexist [Bourne] |
| 14017 | Since presentists treat the presentness of events as basic, simultaneity should be define by that means [Bourne] |
| 2107 | No time exists except instants, and instants are not even a part of time, so time does not exist [Leibniz] |
| 2101 | If everything in the universe happened a year earlier, there would be no discernible difference [Leibniz] |
| 14003 | Time is tensed or tenseless; the latter says all times and objects are real, and there is no passage of time [Bourne] |
| 14005 | B-series objects relate to each other; A-series objects relate to the present [Bourne] |
| 14006 | Time flows, past is fixed, future is open, future is feared but not past, we remember past, we plan future [Bourne] |
| 22894 | If time were absolute that would make God's existence dependent on it [Leibniz, by Bardon] |
| 2099 | The existence of God, and all metaphysics, follows from the Principle of Sufficient Reason [Leibniz] |