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Single Idea 15884

[filed under theme 10. Modality / A. Necessity / 7. Natural Necessity ]

Full Idea

A statement is a law of nature if it is true in all those worlds which differ only as to their initial conditions, that is in which the underlying mechanisms of nature are the same.

Gist of Idea

Laws of nature remain the same through any conditions, if the underlying mechanisms are unchanged

Source

Rom Harré (Laws of Nature [1993], 4)

Book Ref

Harré,Rom: 'Laws of Nature' [Duckworth 1993], p.87

A Reaction

Harré takes it that laws of nature have to be necessary, by definition. I like this way of expressing natural necessity, in terms of 'mechanisms' rather than of 'laws'. Where do the mechanisms get their necessity?

The 27 ideas from 'Laws of Nature'

15869 Reports of experiments eliminate the experimenter, and present results as the behaviour of nature [Harré]
15868 Idealisation idealises all of a thing's properties, but abstraction leaves some of them out [Harré]
15860 We take it that only necessary happenings could be laws [Harré]
15867 Laws describe abstract idealisations, not the actual mess of nature [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]
15872 Must laws of nature be universal, or could they be local? [Harré]
15875 In counterfactuals we keep substances constant, and imagine new situations for them [Harré]
15876 Maybe laws of nature are just relations between properties? [Harré]
15874 Scientific properties are not observed qualities, but the dispositions which create them [Harré]
15879 The Square of Opposition has two contradictory pairs, one contrary pair, and one sub-contrary pair [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]
15878 Some quantifiers, such as 'any', rule out any notion of order within their range [Harré]
15880 In physical sciences particular observations are ordered, but in biology only the classes are ordered [Harré]
15885 The necessity of Newton's First Law derives from the nature of material things, not from a mechanism [Harré]
15884 Laws of nature remain the same through any conditions, if the underlying mechanisms are unchanged [Harré]
15886 Science rests on the principle that nature is a hierarchy of natural kinds [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]
15887 'Grue' introduces a new causal hypothesis - that emeralds can change colour [Harré]
15891 Traditional quantifiers combine ordinary language generality and ontology assumptions [Harré]
15888 The grue problem shows that natural kinds are central to science [Harré]
15892 Laws of nature state necessary connections of things, events and properties, based on models of mechanisms [Harré]