Thursday, July 06, 2006

Saving the phenomena

I’ve been asked to explain myself on scientific antirealism.

Scientific antirealism is as old as Greek philosophy. Greek philosophy distinguished between natural science and mathematical science. Natural science supposedly uncovered the true causes of things, whereas mathematical science was merely consistent with the observable phenomena, and more than one mathematical construct might be empirically adequate or equivalent.

According to scientific realism, our theories are descriptive of reality. Here are a couple of definitions:

“Scientific realists hold that the characteristic product of successful scientific research is knowledge of largely theory-independent phenomena and that such knowledge is possible (indeed actual) even in those cases in which the relevant phenomena are not, in any non-question-begging sense, observable…Scientific realism is thus the common sense (or common science) conception that, subject to a recognition that scientific methods are fallible and that most scientific knowledge is approximate, we are justified in accepting the most secure findings of scientists ‘at face value.’"

“Scientific realism is a view in the philosophy of science about the nature of scientific success, an answer to the question "what does the success of science involve?" The debate over what the success of science involves centers primarily on the status of unobservable entities (objects, processes and events) apparently talked about by scientific theories. Roughly put, scientific realism is the thesis that the unobservable things talked about by science are little different from ordinary observable things (such as tables and chairs).

Scientific realism involves two basic positions. First, it is a set of claims about the features of an ideal scientific theory; an ideal theory is the sort of theory science aims to produce. Second, it is the commitment that science will eventually produce theories very much like an ideal theory and that science has done pretty well thus far in some domains. It is important to note that one might be a scientific realist regarding some sciences while not being a realist regarding others.

According to scientific realism, an ideal scientific theory has the following features:
_ The claims the theory makes about unobservables are either true or false, and they are true or false depending on whether the entities talked about by the theory exist and are correctly described by the theory. This is the semantic commitment of scientific realism.
_ The unobservables described by the scientific theory exist objectively and mind-independently. This is the metaphysical commitment of scientific realism.
_ There are reasons to believe some significant portion of what the theory says about unobservables. This is the epistemological commitment.

Combining the first and the second claim entails that an ideal scientific theory says true things about genuinely existing unobservable entities. The third claim says that we have reasons to believe that the things said about unobservable entities are true.

Scientific realism usually holds that science makes progress, i.e. that scientific theories usually get successively better. For this reason, many people, scientific realist and otherwise, hold that realism should make sense of the progress of science in terms of theories being successively more like the ideal theory that scientific realists describe.”

There are a variety of antirealist alternatives, but the basic idea of scientific antirealism is that our theories are useful fictions.

A Feynman diagram is a good example of a useful fiction. The real world doesn’t resemble a Feynman diagram, yet it’s a very helpful way of modeling quantum interactions.

The fundamental argument in favor of scientific realism is the success of scientific theorizing. Just look at the amazing technological strides that the scientific method has made over the past few centuries.

Surely the scientific method must be on to something. Our theorries must be approximately true to be so successful.

This is a very appealing argument. Ironically, though, the leading objections to scientific realism come from science!

1.There is the question of just how accessible the scientific evidence is to the scientist.

i) We tend to act as if our head was a camera taking snapshots of the world beyond the viewfinder.

On this view, the snapshot resembles the world. Photographical realism distinguishes a photograph from an abstract painting.

But according to a scientific theory of sensation, our perception of the world is far more convoluted.

The mind does not enjoy direct access to the external world. Rather, what we perceive comes to us in the form of encoded and reencoded information, viz. electromagnet information converted to electrochemical information.

If this is true, then our mental representation of the world is more like a cryptogram than a photograph.

ii) Notice, too, that a scientific theory of sensation is somewhat deceptive, if not downright illusory. It describes sensory processing as if the scientist were an independent observer, watching the stimulus impinge on the percipient.

But, of course, he’s really working in reverse. He is, himself, at the receiving end of this process. He is trying to retrace the process.

Yet he’s in no position to objectify the process, for he is unable to escape his own port of entry. Between the sensory input and the conscious readout there lies a blackbox.

How can a scientific theory be truly descriptive of the world if the world is inaccessible to the scientist?

It may seem to be accessible, but that’s the problem. All we have to go by are appearances—appearances several steps removed from the object of our theorizing.

2.Another problem is that a theory may be very successful without making any sense. Quantum mechanics is a textbook example.

The more realistically you interpret quantum mechanics, the more unreal it seems. Einstein and Bohr had a lifeline debate over this issue. Penrose and Hawking are having the very same debate.

3.But that’s not the worst of it. For false theories can be highly successful. Newtonian physics was highly successful. Ether theories were highly successful.

4. There is also the problem of empirical equivalence.

For example, you might think that geocentrism is a lost cause, but consider an exchange I once had with Dr. John Byl (PhD in astronomy from the UBC):

[Hays] As to geocentrism, I don't see that this is even a question of science proper. According to modern astronomy, both the sun and its satellites are in a state of mutual motion, so there is no fixed frame of reference.

In addition, it has always seemed to me that the theories of Mach and Einstein on equivalent forces and equivalent reference-frames would make it easier to defend geocentrism, if one wanted to.

[Byl] Yes. According to general relativity one should get the same observational results, regardless of whether the earth is considered to be at rest, with the rest of the universe revolving about it, or vice versa. (See D. Lynden-Bell et al., "Mach's Principle from the Relativistic Constraint Equations," Monthly Notices of the Royal Astronomical Society, 1995 Vol 272: 150-160).

So realism and antirealism have to answer the same question: how can a mistaken theory be successful?

My own answer is to distinguish between a correlation and a correspondence.

Take a musical CD. If you play a CD, the recording will correspond to a live performance. By that I mean, the recorded sound resembles the live performance.

Now, as we all know, what digital reproduction does is to digitize an audio signal.

So there’s no qualitative resemblance between the binary data and the sound of a live performance. Rather, the sound is encoded in the binary data.

And yet, by that very same token, there is a quantifiable correlation between the input signal and the abstract information which is stored on the disk.

And that’s why it’s possible to reconstruct the original sound from the digital process.

That, in turn, how I would account for the utility of useful fictions. While our perception of the world doesn’t correspond with the world, it does correlate with the world.

That’s how we successfully perceive the world. And that’s how our theoretical constructs, which promote our observations to a higher level of abstraction, can be successful without their being true.

For a few online resources regarding the realist/antirealist debate, cf.:

For a few hardcopy resources, cf.:

Del Ratzsch, Science & Its Limits (IVP 2000)

J. P. Moreland, Christianity & the Nature of Science (Baker 1989)

W. H. Newton-Smith, ed. A Companion to The Philosophy of Science (Blackwell 2001).

Bas Van Fraassen, The Empirical Stance (Yale 2002).


  1. Steve, interesting post. I am a longtime lurker, this is my first comment. Thanks for the great work you and the other T'bloggers do, this is a daily stop for me in my continuing thirst for knowledge.

    It seems as if the antirealist position is somewhat influenced by Hume-like skepticism? My position more closely reflects the thoughts of Thomas Reid, who said "I resolve to take my own existence and the existence of other things upon trust". The trust Reid speaks of is not based on his own reasoning or sensory experience, but is based on his faith in God:"...that God intended that a great and necessary part of our knowledge should be derived from experience". How does that agree or disagree with the antirealist position?

  2. Thanks Steve I can see I'm going to have to convince the wife to increase the book allowance.