Updated:  03 March 2000



UTD - strong thesis


    For any theory T1 there is another theory T2 such that:


    1.     T1, T2 logically incompatible.


    2.     T1, T2 empirically equivalent.


    3.     T1, T2 do equally well in terms of any epistemically viable principle of theory choice.


strong thesis makes IBE problematic





Why believe in UTD ?


1.         Analogy - curve plotting


2.  Freedom to adjust mathematic structure



3. Holism - never test hypothesis in isolation




    hypotheses cannot be tested in isolation.


    alternative responses always possible



    d(t) = gt2


    1.     clock


    2.     ruler


    3.     observer


    4.     value for g


    5.     equation itself


But plausibility of the claim that alternatives always possible depends on plausibility  of thesis of Underdetermination



A couple of asides :


1. Popper :



    In the case of an apparent falsification, how does Popper know what to blame ?


    Could it be that he inductively infers that observers have let him down in the past and hence are not to be trusted on this occasion?   Or that the value of g is ok because the methods used for determining g have been particularly reliable in the past?



2. Edinburgh


strong programme in the sociology of scientific knowledge


Assume only undetermination by actual data. 


Scientists regularly make choices in this situation.  Choice cannot be explained rationally (after all this is underdetermination). So explanation must lie in social factors and/or pyschological ones.




    Role of so-called “pragmatic factors” such as simplicity


    Role of judgment


Problems with strong underdetermination


Notational variants


Absence of examples ?

(no Nobel prizes for second theory)

(density vs continuity)


Speculative Idea ??

inadequate basis for an approach to science


If at best there are limited examples, then at worst realism must be constrained


Instrumentalism as fictionalism



“the easy way to Underdetermination”



T1: There are electrons and ...


T2: There are no electrons but everything happens as if T1 were true.



For the realist T2 self-destructs


Realism is exciting because it takes risks: could be falsified by strong underdetermination


Strong UTD affects both local and global realism.


But it is just a speculation and for the moment the realist can sleep easily.





Why not then use IBE to argue for realism locally ?


Look at your actual history


Mach : talk of atoms is a useful device to facilitate predictions


Einstein: atoms really exist, posited to explain Brownian motion


Ostwald 1905 Preface

    the atomic theory is a device, not to be taken literally


Ostwald 1915 Preface

    atomic hypothesis is true


Einstein - calculated rate of diffusion


Perrin - produced latex particles of known size and shape confirming Einstein

See R Miller Fact and Method








needs novel predictions which are corroborated


plus further theoretical developments with further corroborated novel predictions


Cautious realism


origin of the universe ?


black holes ?







Different stance to theoretical discourse.



Common assumption with realist:

      realism about medium sized macroscopic objects and use of IBE at that level



Instrumentalist has to characterize the realm of discourse to which a different stance is taken.



Characterization of that realm must rationalize the difference in treatment.




Van Fraassen uses a biological characterization.



Churchland queries its relevance.



See his paper in Images of Science



Bas van Fraassen



Douglas van Firrson

(a noted rooted arboreal philosopher with electron microscope eyes)





Why assume that UTD begins at the non-observable as defined by van Fraassen?


Maybe there is only one story until you reach the level of the quark.



electron - via quarks


electron - via krauqs




Where (if anywhere) UTD begins, instrumentalism may be appropriate.



No reason to think that the point at which underdetermination begins is the point at which we are dealing with non-observables.



No reason to drop IBE when we pass over the O/non-O border.



Drop when Underdetermination starts.





Modest Realism


Seamless web argument.



      No dichotomy between ordinary and scientific discourse.  So some reason must be given for thinking that as we move away from ordinary discourse the tools we use there become inappropriate.



      UTD right sort of reason but does not appear extensive enough to really worry the realist.




Challenge to Modest Realism



Explication of notion of approximation to the truth



An Alternative



Current theories more worthy of belief



Some components may be expect to survive



Physics as the exception




Kuhn: puzzle solving



An Alternative to truth or approximate truth?



empirical problems



theoretical problems



real solution requires truth