Combining Texts

Ideas for 'Topics', 'lectures' and 'Laws of Nature'

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2 ideas

10. Modality / A. Necessity / 6. Logical Necessity
Reasoning is when some results follow necessarily from certain claims [Aristotle]
     Full Idea: Reasoning [sullogismos] is a discussion in which, certain things having been laid down, something other than these things necessarily results through them.
     From: Aristotle (Topics [c.331 BCE], 100a25)
     A reaction: This is cited as the standard statement of the nature of logical necessity. One might challenge either the very word 'necessary', or the exact sense of the word employed here. Is it, in fact, metaphysical, or merely analytic?
10. Modality / A. Necessity / 7. Natural Necessity
Laws of nature remain the same through any conditions, if the underlying mechanisms are unchanged [Harré]
     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.
     From: Rom Harré (Laws of Nature [1993], 4)
     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?