display all the ideas for this combination of texts
7 ideas
| 2809 | If nature makes everything for a purpose, then plants and animals must have been made for man [Aristotle] |
| Full Idea: If nature makes nothing without some end in view, nothing to no purpose, it must be that nature has made plants and animals for the sake of man. | |
| From: Aristotle (Politics [c.332 BCE], 1256b20) | |
| A reaction: That was a rather fast move! If a tiger eats a man, how do we explain that? Why are some plants poisonous? Pebbles on a beach seem to have no purpose. |
| 2800 | The best instruments have one purpose, not many [Aristotle] |
| Full Idea: Every instrument will be made best if it serves not many purposes but one. | |
| From: Aristotle (Politics [c.332 BCE], 1252b03) | |
| A reaction: Sound like a good general truth, but not a universal truth. Swiss army knife. Ship in a bottle. Pins. Wrapping paper. |
| 8608 | Counterfactuals 'backtrack' if a different present implies a different past [Lewis] |
| Full Idea: A counterfactual can be said to 'backtrack' if it can be said that if the present were different a different past would have led up to it (rather than if the present were different, the same past would have had a different outcome). | |
| From: David Lewis (New work for a theory of universals [1983], 'Dup,Sup,Div') | |
| A reaction: A nice clear definition of a concept which is important in Lewis's analysis of causation. In the current context he is concerned with elucidation of determinism and materialism. I would say (intuitively) that all counterfactuals backtrack. |
| 8584 | Causal counterfactuals must avoid backtracking, to avoid epiphenomena and preemption [Lewis] |
| Full Idea: My counterfactual analysis of causation needs counterfactuals that avoid backtracking; else the analysis faces fatal counterexamples involving epiphenomenal side-effects or cases of causal preemption. | |
| From: David Lewis (New work for a theory of universals [1983], 'Laws and C') | |
| A reaction: The concept of true epiphenomena (absolutely no causal powers) strikes me as bogus. |
| 8581 | Physics discovers laws and causal explanations, and also the natural properties required [Lewis] |
| Full Idea: Physics must not just discover laws and causal explanations. In putting forward as comprehensive theories that recognise only a limited range of natural properties, physics proposes inventories of the natural properties instantiated in our world. | |
| From: David Lewis (New work for a theory of universals [1983], 'Min Mat') | |
| A reaction: Physics does this job extremely well, offering things like force, spin, charge that are the building blocks for their theories. There is metaphysics at the heart of physics, unavoidably. |
| 15727 | Physics aims for a list of natural properties [Lewis] |
| Full Idea: Physics aspires to give an inventory of natural properties. | |
| From: David Lewis (New work for a theory of universals [1983], 'Dup,Sup,Div') | |
| A reaction: The sort of beautifully simple remark by which philosophers ought to earn a good living in the intellectual community. Come on physicists - this is all we want! Presumably the inventory will include an account of how they all work. |
| 8611 | A law of nature is any regularity that earns inclusion in the ideal system [Lewis] |
| Full Idea: A law of nature is any regularity that earns inclusion in the ideal system (or, in case of ties, in every ideal system). | |
| From: David Lewis (New work for a theory of universals [1983], 'Laws and C') | |
| A reaction: Reminiscent of Peirce's view of truth (Idea 7661). This wouldn't seem to eliminate the danger of regularities with underlying causes ending up as laws (day causes night). Or very trivial regularities ending up as laws. |