56 ideas
| 15879 | The Square of Opposition has two contradictory pairs, one contrary pair, and one sub-contrary pair [Harré] |
| 14970 | Normal system K has five axioms and rules [Cresswell] |
| 14971 | D is valid on every serial frame, but not where there are dead ends [Cresswell] |
| 14972 | S4 has 14 modalities, and always reduces to a maximum of three modal operators [Cresswell] |
| 14973 | In S5 all the long complex modalities reduce to just three, and their negations [Cresswell] |
| 14976 | Reject the Barcan if quantifiers are confined to worlds, and different things exist in other worlds [Cresswell] |
| 15891 | Traditional quantifiers combine ordinary language generality and ontology assumptions [Harré] |
| 15878 | Some quantifiers, such as 'any', rule out any notion of order within their range [Harré] |
| 458 | Nothing could come out of nothing, and existence could never completely cease [Empedocles] |
| 5112 | Empedocles says things are at rest, unless love unites them, or hatred splits them [Empedocles, by Aristotle] |
| 14974 | A relation is 'Euclidean' if aRb and aRc imply bRc [Cresswell] |
| 15874 | Scientific properties are not observed qualities, but the dispositions which create them [Harré] |
| 13209 | There is no coming-to-be of anything, but only mixing and separating [Empedocles, by Aristotle] |
| 457 | Substance is not created or destroyed in mortals, but there is only mixing and exchange [Empedocles] |
| 14975 | A de dicto necessity is true in all worlds, but not necessarily of the same thing in each world [Cresswell] |
| 15884 | Laws of nature remain the same through any conditions, if the underlying mechanisms are unchanged [Harré] |
| 462 | One vision is produced by both eyes [Empedocles] |
| 15880 | In physical sciences particular observations are ordered, but in biology only the classes are ordered [Harré] |
| 15869 | Reports of experiments eliminate the experimenter, and present results as the behaviour of nature [Harré] |
| 15881 | We can save laws from counter-instances by treating the latter as analytic definitions [Harré] |
| 15882 | Since there are three different dimensions for generalising laws, no one system of logic can cover them [Harré] |
| 15888 | The grue problem shows that natural kinds are central to science [Harré] |
| 15887 | 'Grue' introduces a new causal hypothesis - that emeralds can change colour [Harré] |
| 15889 | It is because ravens are birds that their species and their colour might be connected [Harré] |
| 15890 | Non-black non-ravens just aren't part of the presuppositions of 'all ravens are black' [Harré] |
| 15885 | The necessity of Newton's First Law derives from the nature of material things, not from a mechanism [Harré] |
| 15868 | Idealisation idealises all of a thing's properties, but abstraction leaves some of them out [Harré] |
| 22765 | Wisdom and thought are shared by all things [Empedocles] |
| 1524 | For Empedocles thinking is almost identical to perception [Empedocles, by Theophrastus] |
| 552 | Empedocles said good and evil were the basic principles [Empedocles, by Aristotle] |
| 589 | 'Nature' is just a word invented by people [Empedocles] |
| 21823 | The principle of 'Friendship' in Empedocles is the One, and is bodiless [Empedocles, by Plotinus] |
| 2680 | Empedocles said that there are four material elements, and two further creative elements [Empedocles, by Aristotle] |
| 6002 | Empedocles says bone is water, fire and earth in ratio 2:4:2 [Empedocles, by Inwood] |
| 13207 | Fire, Water, Air and Earth are elements, being simple as well as homoeomerous [Empedocles, by Aristotle] |
| 459 | All change is unity through love or division through hate [Empedocles] |
| 13218 | The elements combine in coming-to-be, but how do the elements themselves come-to-be? [Aristotle on Empedocles] |
| 13225 | Love and Strife only explain movement if their effects are distinctive [Aristotle on Empedocles] |
| 460 | If the one Being ever diminishes it would no longer exist, and what could ever increase it? [Empedocles] |
| 15886 | Science rests on the principle that nature is a hierarchy of natural kinds [Harré] |
| 15864 | Classification is just as important as laws in natural science [Harré] |
| 15865 | Newton's First Law cannot be demonstrated experimentally, as that needs absence of external forces [Harré] |
| 15862 | Laws can come from data, from theory, from imagination and concepts, or from procedures [Harré] |
| 15870 | Are laws of nature about events, or types and universals, or dispositions, or all three? [Harré] |
| 15871 | Are laws about what has or might happen, or do they also cover all the possibilities? [Harré] |
| 15876 | Maybe laws of nature are just relations between properties? [Harré] |
| 15860 | We take it that only necessary happenings could be laws [Harré] |
| 15872 | Must laws of nature be universal, or could they be local? [Harré] |
| 15867 | Laws describe abstract idealisations, not the actual mess of nature [Harré] |
| 15892 | Laws of nature state necessary connections of things, events and properties, based on models of mechanisms [Harré] |
| 15875 | In counterfactuals we keep substances constant, and imagine new situations for them [Harré] |
| 5090 | Maybe bodies are designed by accident, and the creatures that don't work are destroyed [Empedocles, by Aristotle] |
| 466 | God is pure mind permeating the universe [Empedocles] |
| 461 | God is a pure, solitary, and eternal sphere [Empedocles] |
| 1719 | In Empedocles' theory God is ignorant because, unlike humans, he doesn't know one of the elements (strife) [Aristotle on Empedocles] |
| 1522 | It is wretched not to want to think clearly about the gods [Empedocles] |