Note that the “heretic” in the title refers to me, and comes from this blog’s title.
I have long considered myself a scientific realist. At least, on some definitions, a scientific realist is one who believes that science provides the best available descriptions of the natural world. And, in that sense, I surely am a scientific realist.
I’ve been noticing that some people have been suggesting that I am an instrumentalist or an anti-realist. So they must be using a different notion of “scientific realism.” There’s a post, today, at Scientia Salon which gets into such an account of scientific realism:
Here, I will discuss that post and where I have difficulty with the way that it looks at science. My own view of science, and how it works, should be apparent from that discussion. And I think it will be clear that my own view is non-standard (and, in that sense, heretical).
The standard picture
The opening paragraphs of the cited post already suggest the standard view from philosophy of science. It poses the “problem” of scientific realism in the form of the question “what is the status of scientific theories?” It then breaks this down into details, and I’ll comment on those:
- Should they [scientific theories] be interpreted as literal descriptions of reality?
To that, I’ll answer “No”.
- Or are they rather predictive instruments, tools for interacting with reality?
I can go along with the idea that they are tools for interacting with reality, but I’m not so sure about the “predictive instruments” part of that.
- Or perhaps they are mere social constructions?
There’s no doubt that they are social constructions, but there is nothing “mere” about them.
The author then divides the question into metaphysics, semantics and epistemology. So I’ll separately look at those.
Metaphysical question: does nature, the object of scientific inquiry, exist independently of our conception and observations of it? Idealists and radical constructivists would deny that it does.
I’m a skeptic of metaphysics, and this metaphysical question is no exception. It seems to me that the question is vacuous. The only meaning we have for “exist” is one based on our experience. So any talk of “exist” can only be about our conception of reality. We cannot get outside of that.
Some people suggest a God’s eye view, that we take “exist” as it would be to an imagined God. But we create our gods in our own image, so the gods that we imagine are as limited by our conception of reality as we are.
I will say that I am not an idealist, and I do not take myself to be a radical constructivist. I see theories as constructs, but I do not see reality itself as a construct. However, we are still unavoidably limited by our own conception of reality.
Semantic question: what makes theories true? Are they literal descriptions of nature? Is there a direct correspondence between language (including formal languages or mathematical models) and the fundamental constitution of nature, or does the meaning of our theoretical statements reduce to their conditions of verification? Instrumentalists would typically opt for the latter view.
There’s already a complexity here. We use the term “theory” rather broadly, and theories are not all of the same nature. So I’ll mainly be commenting on what I see as the most ideal theories. I would put Newtonian mechanics in that class.
So now look at the details of that question:
- what makes theories true?
Edict; authoritative assertion.
I see theories (or ideal theories) as analytic truths. That is, they are true by virtue of the meanings of the terms that they use and define. So, in some sense, they declare their own truth.
- Is there a direct correspondence between language (including formal languages or mathematical models) and the fundamental constitution of nature
Yes. But this is where I most strongly disagree with the standard view. You cannot say that statements correspond to reality unless there are some principles of correspondence available. As I see it, the primary role of science is to establish those principles of correspondence.
Take, for example, Newton’s laws. They allowed us to talk about the force of air resistance or the force of friction. They allowed us to assign numeric values to these forces. So they established a correspondence between statements we could make and what is happening in reality.
It is this establishing of a correspondence that makes our theories analytic truths. And it is also what makes our theories valuable.
Epistemic question: are we in a position to know that our theories are at least approximatively true? Empiricists would say that, inasmuch as our theories pretend to say more than what is verifiable at the level of observable phenomena, we are not in a position to know that they are any more true than (perhaps unconceived) alternative theories with as much empirical confirmation.
If our theories are analytic, then they are true. However, my preference is to say that they are neither true nor false. Their real role is to establish a correspondence, such as would make it possible to have observation statements that follow such a correspondence. And those observation statements are true to the extent that they follow the correspondence defined by the theory.
However, it is not sufficient for our theories to be true (in the sense of analytic truth). We also want them to be useful. They establish a correspondence, but for the theory to be useful, that correspondence must enable useful observation statements. So there is a strong pragmatic requirement for a scientific theory.
Theory change, then, amounts to a change of our principles of correspondence. The change from geocentrism to heliocentrism is a classic example of this. We typically make the change on a pragmatic base. We change theories when the new theory provides a more useful or more comprehensive correspondence between the statements that we can make and reality.
How science works
The author of the Scientia Salon post goes on to say:
One of the main arguments for scientific realism, once formulated by Putnam, is that realism is the only position that does not make a miracle of the predictive success of science. The point being that anti-realists have no convincing explanation for the impressive success of science (notably for making novel, unexpected predictions), while realists have a simple one: our theories work because they correctly describe reality.
This seems mistaken, to me. To say that scientific theories need to be descriptions of reality, is to say that scientists are akin to journalists. In some sense, it sees scientists as journalists reporting on the natural world.
We do not expect journalism to lead to a lot of useful predictions. So it is not obvious that a journalism of nature would lead to predictions.
Historically, before our modern scientific era, science (then called natural philosophy) was close to being a journalism of nature. And it did not have the degree of predictive success that we have seen in modern science.
My view is that science works so well, specifically because it establishes correspondences between nature and our description. This establishing of correspondences has allowed us to describe the world if far more detail than was previously possible. It is the extra information, due to this increased detail, that I see as the basis for the success of science.