Put very simplistically, there is a tension between two broad approaches to science: (constructive) empiricism and (scientific) realism.1 The former states that we should take our scientific theories to be no more than adequate descriptions of the phenomena under investigation, whilst the latter commits science to the literal truth of its theories, and by extension to the existence of the unobservable entities that they describe. For example, the realist is committed to the actual existence of sub-atomic particles, whilst the empiricist will merely use them as part of the description of a contingently accurate theory, without making any judgement as to whether or not they exist.2
Both approaches appear to be flawed (although in ways more complicated than the following paragraph might suggest). Realism is committed to the existence of entities that are likely to turn out not to exist, or not to exist in quite the way that we thought they did. As science progresses, some of these entities become redundant, implying a level of discontinuity between theories that in practice is not manifested. Empiricism, meanwhile, struggles to explain why these entities have any explanatory power, if in fact they're not real (it also risks descent into total relativism). Ladyman et al present structural realism as almost a dialectical synthesis of these two approaches, but for now I'll simply try and break down my own understanding of it.
Realism: Scientific theories do attempt to describe some underlying reality, although of course they are often wrong. Contra empiricism, they are more than just a conveniently accurate account of observable phenomena.
Structural: However, it is not unobservable entities per se that these theories are committed to, but rather the structural relationships between them (if indeed they exist at all). This structure is what underlies reality, and is what science seeks to describe. Whilst theory change requires abandoning some entities, the structure of the previous theory can be retained. Thus, Ladyman et al describe how both successive theories and theories at different explanatory levels can be related in terms of mathematical structure rather than direct one-to-one mapping of entities and propositions (2007: 118).
Pragmatic: Science is an ongoing process, and so we must recognise the commitments of our current theories as pragmatic place-holders rather than absolute certainties. These theories are our best guess at the structure of reality, and we adapt them as new evidence becomes available. Furthermore, our commitment to structural realism is itself pragmatic, motivated by our belief that it best describes actual scientific (and epistemic) practice.
How is this relevant to the philosophy of mind? Well, for one thing I'm keen to make sure that my understanding of the mind is based on an accurate understanding of science. It's important to ensure that we know what we're on about when try to describe the physical instantiation of the mind. On one level this calls for an understanding of psychology and neuroscience, but on another it means coming to grips, at least in basic sense, with physics. All science essentially boils down to physics of some description, and even if we're quickly going to abstract away from that fundamental level, I think we need to understand it first. Otherwise our entire project is going to rest on faulty foundations.
James Ladyman strikes me as someone who's got a very clear grasp of both contemporary science and the muddled attempts of philosophers to try and make sense of it. His 2010 paper (with Don Ross) on appeals to scientific practice in the extended mind debate really struck home for me, and Everything Must Go is more of the same, although heavy going at times. I'm looking forward to hearing him speak at this conference in a week's time, and I'll maybe report back with some further thoughts after that.
1. This terminology is somewhat misleading, as strictly speaking scientific realists are also empiricists. The difference lies in what they believe to exist, not how they advocate studying it.
2. Complicating things further is the apparent failure of modern philosophy to appreciate the nature of contemporary physics. We tend to talk of physics as though it studies discrete, although very small, objects. According to Ladyman et al this is incorrect, and more importantly philosophically unhelpful.
- Ladyman, J., Ross, D., Spurrett, D. & Collier, J. 2007. Everything Must Go. Oxford: OUP.
- Ross, D & Ladyman, J. 2010 "The Alleged Coupling-Constitution Fallacy and the Mature Sciences." In The Extended Mind, ed. Menary. Cambridge, MA: MIT Press.
