For a regularly updated
bibliography click here: Structural
Realism Bibliography
For a longer exposition, take a look at my quasi-historical 'Tracing the
Development of Structural Realism' but also
James Ladyman's entry in the Stanford Encyclopaedia of Philosophy.
A very brief account:
Three major kinds of structural realism can be identified, each with
its own satellite variants:
(1) Epistemic Structural Realism, or ESR for
short, holds that our epistemic access is restricted to structural
features of the world. The position can be traced back at least to the
beginning of the 20th century, namely to the independent work of Henri
Poincaré and Bertrand Russell.
Russell’s structuralist inclinations can be seen as early as The
Problems of Philosophy (1912). A fully-fledged account only emerged in
The Analysis of Matter (1927). There he argued that there are external
causes to our perception, admitting that we should “not expect to find
a demonstration that perceptions have external causes” (1927, 198). The
twentieth chapter of this book is devoted to a causal theory of
perception, rejecting “the view that perception gives direct knowledge
of external objects” (1927, 197). We only have direct epistemic access
to percepts, i.e. the items of our perception. The only way to attain
knowledge of the external world is to draw inferences from our
perceptions. To underwrite such inferences Russell employed a number of
principles. The most important of these are:
Helmholtz-Weyl Principle (H-W): Different effects (i.e. percepts) imply
different causes (i.e. stimuli/physical objects)) (1927, 255).*
Mirroring Relations Principle (MR): Relations between percepts mirror
(i.e. have the same logico-mathematical properties as) relations
between their non-perceptual causes (1927, 252).
Armed with these assumptions Russell argues that from the structure of
our perceptions we can “infer a great deal as to the structure of the
physical world, but not as to its intrinsic character” (1927, 400).
More precisely, he argues that there is at most an isomorphic relation
between the structure of our perceptions and the structure of the
physical world.
The recent interest in structural realism was instigated by the
publication of John Worrall’s ‘Structural Realism: The Best of Both
Worlds?’ in 1989. The article is inspired by Poincaré’s brand of ESR
which is more sensitive to the history of science. Worrall associates
the search for a lasting solution to the scientific realism debate with
the need to take into consideration two warring arguments: the
no-miracles argument (NMA) and the pessimistic meta-induction argument
(PMI). In short, PMI holds that since predictively successful
scientific theories have eventually been discarded, we have inductive
evidence that even our current theories, despite being even more
successful, will also be discarded one day. NMA holds that realism is
the only view that does not make the predictive success of science a
miracle. Worrall offers ESR as a weaker (in terms of epistemic
commitments) but more justifiable realist position that underwrites
both of these arguments, and situates itself midway between
constructive empiricism and traditional scientific realism. It
underwrites the NMA because it argues that the success of science
reflects the fact that we have got the structure of the world right. It
underwrites the PMI because it concedes that although there is radical
discontinuity in theory change, viz. where non-structural descriptions
of the nature of entities are involved, there is also considerable
continuity at the structural level.
Stathis Psillos calls the Russellian approach the ‘upward path’ to
structural realism, in contrast to the Poincaréan/Worrallian approach
or ‘downward path’ to structural realism. One important difference lies
in the way the two views are motivated. The Poincaréan approach takes
the preservation of structure through theory change as indicative of
its truth/approximate truth. The Russellian approach looks not in
history but in perception to provide a reconstruction of our
non-perceptual knowledge about the world. Another related difference
concerns the way in which structure gets demarcated. Worrall and Elie
Zahar (2001) favour the Ramsey sentence approach, while Ioannis Votsis
(2003, 2005) rejects it in favour of the notion of abstract structure
as it is explicated in Michael Redhead (2001). Of course the
disagreement is not merely a question of which formal tools are best
equipped for the job of representing the structure of the world but
also a question of how to draw the line between the structural and the
non-structural.
(2) Ontic Structural Realism, or OSR for short,
holds that our ontology is in some sense primarily structural in
nature. If this sounds sufficiently ambiguous, it is because there are
so many different variants of OSR that it is difficult to formulate a
commonly shared view.
OSR was proposed by James Ladyman (1998). The view was subsequently
developed jointly with Steven French. Together they argue that
structural realism should be understood not just as an epistemic but
also as an ontic position. The motivation for OSR draws on
underdetermination in modern, and particularly in quantum, physics.
Although originally promoted as the view that only structures exist,
i.e. objects can be no more than heuristic vehicles, the position has
mutated into a number of different variants. One such variant, which we
can call the ‘no individuals view’, denies the existence of individuals
but accepts the existence of objects and structures. If you’re
wondering what sort of objects these are, they are those for which the
law of identity does not hold (see, for example, Steven French and
Decio Krause 2006). Another variant, which we can call the ‘no
intrinsic natures view’, holds that there exist no intrinsic natures,
only haecceity-free individuals and structures (e.g. Ladyman et al.
2007). These two as well as the other main OSR alternatives are
wonderfully sketched out in Ladyman’s Structural Realism entry in the
Stanford Encyclopaedia of Philosophy (2007).
(3) Methodological Structural Realism, or MSR for
short, is the most recent kind of structural realism to be proposed. As
its name suggests, MSR concentrates on the role shared structure plays
in characterising scientific theories, in relating high-level theory to
low-level data and in identifying links between predecessor and
successor theories (see Katherine Brading and Elaine Landry 2006).
Endnote:
* The name 'Helmholtz-Weyl' is given by Stathis Psillos (2001) because,
according to him, it was they "who first enunciated it". Though I kept
the name, the principle goes at least as far back as Descartes. Hume
advertises in the Treatise that “Like causes still produce like
effects” (Book II, Part III, §1). This is the H-W principle in
contrapositive form. Similarly, Descartes in the sixth Meditation says:
"I safely conclude that there are in the bodies from which the diverse
perceptions of the senses proceed, certain varieties corresponding to
them, although, perhaps, not in reality like them; and since, among
these diverse perceptions of the senses, some are agreeable, and others
disagreeable, there can be no doubt that my body, or rather my entire
self, in as far as I am composed of body and mind, may be variously
affected, both beneficially and hurtfully, by surrounding bodies".
References:
Brading, K. and E. Landry (2006), ‘Scientific Structuralism:
Presentation and Representation’, Philosophy of Science, vol.
73(5):571-581.
French, S. and D. Krause (2006), Identity in Physics: A Historical,
Philosophical and Formal Analysis, Oxford: Oxford University Press.
Ladyman, J. (1998), ‘What is Structural Realism?’, Studies in History
and Philosophy of Science, vol. 29: 409-424.
Ladyman, J. (2007), ‘Structural Realism’, The Stanford Encyclopedia of
Philosophy, Edward N. Zalta (ed.), URL
=http://plato.stanford.edu/entries/structural-realism/
Ladyman, J. and D. Ross (with D. Spurrett and J. Collier) (2007), Every
Thing Must Go: Metaphysics Naturalised, Oxford: Oxford University Press.
Poincaré, H. ([1905]1952), Science and Hypothesis, New York: Dover.
Psillos, S. (2001), ‘Is Structural Realism Possible?’, Philosophy of
Science, vol. 68: S13-24.
Redhead, M.L.G. (2001), ‘The Intelligibility of the Universe’, in
A.O'Hear (ed) Philosophy at the New Millennium, Cambridge: Cambridge
University Press.
Russell, B. (1912), The Problems of Philosophy, Oxford: Oxford
University Press.
Russell, B. (1927) The Analysis of Matter, London: George Allen
& Unwin.
Votsis, I. (2003), ‘Is Structure not Enough?’, Philosophy of Science,
vol. 70(5): 879-890.
Votsis, I. (2005), ‘The Upward Path to Structural Realism’, Philosophy
of Science, vol. 72(5): 1361-1372.
Worrall, J. (1989), ‘Structural Realism: The Best of Both Worlds?’ in
Papineau, D. (ed.) The Philosophy of Science, Oxford: Oxford University
Press, 1996.
Worrall, J. and E. Zahar (2001), ‘Ramseyfication and Structural
Realism’, Appendix IV in E. Zahar, Poincare’s Philosophy: From
Conventionalism to Phenomenology, Chicago and La Salle (IL): Open Court.
