Introduction and Background Nancy Cartwright’s New Philosophy of Science: Cartwright’s Argument for anti-fundamentalism Conclusion and Future work
Role of fundamental Laws in Nancy Cartwright’s Philosophy of science Subtitle
A. V. Ravishankar Sarma
IIT Kanpur
7 December 2007
1 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Outline
1 Introduction and Background Fundamental Laws of Physics and Received Views
2 Nancy Cartwright’s New Philosophy of Science: Main Theses
3 Cartwright’s Argument for anti-fundamentalism Simulacrum account of explanation
4 Conclusion and Future work
2 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Fundamental Laws of Physics and Received Views Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Aim
What Role fundamental laws play in Cartwright’s philosophy of science? to present Cartwright’s argument for the anti-fundamentalism regarding laws of nature. What would be the appropriate way of dealing with Laws that explain current activities in Physics. How the falsity doctrine of Cartwright influence covering Law model of explanation? To show that not all laws of physics lie.
3 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Fundamental Laws of Physics and Received Views Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Who is Nancy Cartwright?
Nancy Cartwright (1943- ) Approach to Philosophy of science: Stanford school of John Dupre, Peter Galison, Ian Hacking. Her approach: Practical empiricism (a sort of Anti-Realism). Denies fundamentalism. Laws doesn’t get the facts right.
4 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Fundamental Laws of Physics and Received Views Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Laws of Nature
Science aims to discover Laws. (Laws of motion, inverse square law, conservation of mass and energy, symmetry principles. Account of laws purport to give us (1) a theory of explanation (2) a theory of confirmation (3) an explication of necessity (4) Laws a way of understanding science, its aim and structure. Laws describe regularities and patterns to be found in the world. What if there are no laws?
5 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Fundamental Laws of Physics and Received Views Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Richard Feynman
There is a rhythm and a pattern behind the phenomena of nature which is not apparent to the eye, but only to the eye of analysis; and it is these rhythms and patterns which we call Physical Laws. . . . Feynman: The character of Physical Law.
6 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Fundamental Laws of Physics and Received Views Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Fundamental and Phenomenological Laws
Phenomenological laws are laws about appearances. We can at least in principle observe them. Theoretical laws are about the reality behind the appearances. It can be known by indirect experience. Phenomenological laws are true of the objects of reality- or might be. but the fundamental laws are true only of the objects in the model(page 4).
7 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Fundamental Laws of Physics and Received Views Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Received Views
Regularity View: Hume: Laws are universal Generalizations Necessity: Armstrong, David Lewis(Modalized generalization with necessity operator) Anti-realists: Bas van Fraassen, Ronald Geire Nancy Cartwright: Patch Wok of laws Anti fundamentalist (denies facticity view of laws)
8 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Main Theses Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Cartwright’s philosophy of science
Philosophy of science: Theory, models, World of objects. Advocates a kind of practical empiricism. Her position is realist on entities(like Hacking), and Anti-realist on the theoretical laws of physics. Practical Empiricism seeks to make difference to how science carries on. Unlike semantic view, her main concern is not with meaning but the method. Nancy Cartwright maintains that the content of science is found not just in its laws but equally in its practices. One of her general claim is that our beliefs about the structure of the world go hand-in-hand with the methodologies we adopt to study it.
9 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Main Theses Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Main Theses
The fundamental Laws of Physics are not true(Universal law of gravitation, Maxwell’s equation, Schrodinger equation) Nevertheless, fundamental laws of physics are explanatory. The phenomenological laws of physics are (tend to be) true. Though not true of the physical world, theoretical laws do describe simulacra- or models- simplified, false, manageable constructs by means of which explanation in physics proceeds. Physical theories or physics theories as Cartwright calls them are not deductive structures. Inference to the best explanation is fallacious and cannot justify beliefs in the truth of theoretical laws in physics.
10 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Simulacrum account of explanation Cartwright’s Argument for anti-fundamentalism Conclusion and Future work How the laws of Physics lie?
F= G m1 m2/r2 interpreted literally is false. Interpret the law as including a ceteris paribus modifier (.i.e if there are no forces other than gravity at work, then F= G m1 m2/r2 Interpret the law as describing a component force (i.e the force due to gravity Fg= G m1m2/r2. Cartwright rejects the second. If we interpret as (1) then their antecedent conditions that are almost never satisfied.
11 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Simulacrum account of explanation Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Argument
The fundamental laws of physics are true only when appropriate ceteris paribus modifiers are attached. Ceteris paribus modifiers describe conditions that hold only under ideal situations. When the fundamental laws of physics are true, they apply to objects in ideal(counterfactual) situations. Therefore, the fundamental laws of physics dont apply to objects in the real world. Result: We consider law-like statements of science to apply in a highly qualified ways within narrow, non overlapping and ontological domains.
12 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Simulacrum account of explanation Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Why take Fundamental Laws of physics to be false?
Cartwright’s argument: Fundamental laws of physics are false because of the composition of forces, or more generally, because of the composition of causes as described by theoretical laws. Note: Fundamental or Theoretical mean dynamic laws. Example: Imagine a classically charged particle moving under the influence of forces in the real world. Gravitational and electromagnetic forces add vectorially to produce resultant acceleration and force of the particle. . But the accelerations due to each separate force do not appear to occur. Brief Argument: When causes combine they disappear, when the forces add vectorially they too disappear and so fail to state the facts.
13 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Simulacrum account of explanation Cartwright’s Argument for anti-fundamentalism Conclusion and Future work When Fundamental laws becomes true
the fundamental laws of physics are true when and only when appropriate ceteris paribus modifiers are attached. ceteris paribus modifiers describe conditions that are almost never satisfied. Cartwright concludes that when the fundamental laws of physics are true, they don’t applying the real world, but only in highly idealized counterfactual situations. example: F= Ma
14 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Simulacrum account of explanation Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Deductive Nomological explanation
A model of explanation associated especially with German logician Carl Gustav Hempel (1905-1997), who regarded it as adequate for all types of explanation. f1 explains f2 when of2 induces the occurrence of of1 by means of a law of nature. Basically a statement is explained if it is derived from a set of laws together with certain factual statements (initial rules of logic). 1. fundamental laws are false. 2. number of explanations in physics does not invoke laws. They are best covered by ceteris paribus - generalizations that hold for special conditions. major premise in the covering laws explanation is false. From false antecedent any thing follows.
15 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Simulacrum account of explanation Cartwright’s Argument for anti-fundamentalism Conclusion and Future work How the fundamental Laws explain
The fundamental Laws explain but do not describe facts. Two troubles: They let in too little 2. covering laws are too scarce. They let in too little- since there are no fundamental covering laws-true fundamental laws- and there are two few true phenomenological laws to provide adequate cover. Example: The over simple law of Snell enables us to explain the typically anisotropic real world of which it is false.
16 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Simulacrum account of explanation Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Quote
Ceteris paribus generalizations, read literally without the ceteris paribus modifier, are false. They are not only false, but held by us to be false; and there is no ground in the covering law picture for false laws to explain anything. On the other hand, with the modifier the ceteris paribus generalizations may be true, but they cover only those few cases where the conditions are right. For most cases, either we have a law that purports to cover, but cannot explain because it is acknowledged to be false, or we have a law that does not cover. Either way, it is bad for the covering-law picture. (Cartwright 1983, 45–46)
17 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Simulacrum account of explanation Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Simulacra account of explanation
Cartwright’s goal was to show that laws that contain idealizations cannot be used in covering-law explanations. The value described in the explanandum is close to the value predicted by the idealization. Covering law model ties laws directly to reality. A good theory aim to cover a wide variety of phenomena with as few principles as possible that includes bridge principles. Example: Quantum mechanics (few Hamiltonians are used). OED: It is something having merely the form or appearance of a certain thing, without possessing its substance or proper qualities. To explain a phenomena is to find a model that fits into basic framework of the theory and thus allows us to derive analogues for the messy and complicated phenomenological laws which18 are true of it. Introduction and Background Nancy Cartwright’s New Philosophy of Science: Simulacrum account of explanation Cartwright’s Argument for anti-fundamentalism Conclusion and Future work
The route from theory to reality is from theory to model, and then from model to phenomenological law. We lay out a model and within the model we derive various laws which match more or less well with bits of phenomenological behavior. The success of model depends upon how much and how precisely it can replicate what goes on. A model is a work of fiction.
19 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Simulacrum account of explanation Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Dappled World Hypotheses
We live in a dappled world, a world rich in different things, with different natures, behaving different ways. Laws describe this world are a patchwork, not a pyramid. They do not take after the simple, elegant and abstract structure of the system of axioms and theorems.
20 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Simulacrum account of explanation Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Dappled Word- contd
Dappled World is a world that displays some features which are precisely ordered, whereas other features are un- ruly (1999, 10). This picture of a dappled world is drawn from an analysis of the way science, and in particular physics, actually works. And the punchline in this analysis is the claim that physics cannot account for everything that is in its domain (2001, 210). These methodologies are governed by capacities and without which we cannot make an sense. She also insists that practical empiricism of measurement is the most radical empiricism that makes sense in science. Such a framework is in complete harmony with causes and capacities.
21 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Summary
Fundamental laws explains but do not describe facts. Showed How fundamental laws do not get the facts correct. Argued for Anti-fundamentalist position of Cartwright with examples form the domain of physics Conventional D-N account have to go. A good theory of physics should aim to cover wide variety of phenomena with as few principles as possible. We need to view world as dappled and to treat capacities as central than that of Laws.
22 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Future Work
To elaborate simulacrum account of explanation by taking examples from physics. On the one hand we have theory of everything, grand unification of forces and the other following Cartwright we have a a notion of physics which seeks disunity anti fundamentalism, patch work of laws. In a nutshell it works in blocks. How one strikes a balance? To analyze ceteris paribus modifies and explain how its presence makes the fundamental law true How we explain abductions in a physical world, if we dismiss inference to the best explanation?
23 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Compact Bibliography
Cartwright, N.: 1983, How the Laws of Physics Lie, Clarendon Press, Oxford. Cartwright, N.: 1999, The Dappled World: A Study of the Boundaries of Science, Cambridge University Press, Cambridge. Chalmers, A.: 1993, So the Laws of Physics Needn’tt Lie, Australasian Journal of Philosophy 71, 196–207. Feynman, Richard P. (1965), The Character of Physical Law. Cambridge: M.I.T. Press.
24 Introduction and Background Nancy Cartwright’s New Philosophy of Science: Cartwright’s Argument for anti-fundamentalism Conclusion and Future work Thanks!!
Thanks for your attention!
Slides for this talk will be available at: http://home.iitk.ac.in/~avrs/PhilTea/
Role of fundamental Laws in Nancy Cartwright’s Philosophy of science Subtitle
A. V. Ravishankar Sarma 25 IIT Kanpur
7 December 2007