24 April, 2015
Last night and today I have dipped into Bas van Fraasen’s book The Scientific Image, a classic philosophy of science text from 1980 where he presents and develops an empiricist alternative (what he calls ‘Constructive Empiricism’) to scientific realism. Both are intriguing perspectives within Philosophy of Science worth thinking about when it comes to understanding the relationship between science and the world.
Before going any further, one should have a definition of both ’empiricism’ and ‘scientific realism.’ We can define Empiricism simply as: “the only source of real knowledge about the world is experience” (Godfrey-Smith, p.8). Expanding upon this by combining Empiricism with Science we have: “Scientific thinking and investigation have the same basic pattern as everyday thinking and investigation. In each case, the only source of real knowledge about the world is experience. But science is especially successful because it is organized, systematic, and especially responsive to experience” (ibid).
By comparison, a workable definition of ‘scientific realism’ would be: “[T]here is a real world that we all inhabit and that one reasonable goal of science is describing what the world is like” (Godfrey-Smith, p.241). Put another way, the world that science describes to us is the real world (we will see van Fraassen’s perspective on this below).
As a means for developing an alternative to scientific realism, van Fraassen seeks to put forward three theories which use each other for support:
1. A relation of a theory to the world.
2. A theory of scientific explanation.
3. An explication of probability as it occurs within physical theory (van Fraassen, p.vii).
At the very beginning of the introduction he asks “what sort of philosophical account is possible of the aim and structure of science?” (p.2). He divides philosophy of science into two parts:
(i) foundational issues which are concerned with the content and structures of scientific theories, and
(ii) the relations theories have to the world and the user of the theory (ibid).
These views, in his mind, aim to provide us with “a true description of unobservable processes that explain the observable ones, and also of what are possible states of affairs, not just of what is actual” (p.3). The problem that arises with empiricism, he claims, is that that it requires theories to give us an account of only what is observable.
If we are pondering what the relation is between a theory and the world, then one concern that might arise is to ask what is involved in ‘accepting’ a scientific theory – “how much belief is involved in theory acceptance” (p.4). On the ‘Constructive Empiricist’ view that van Fraassen wants to develop, this belief serves only to ‘save the phenomena,’ which as the empirical position states according to van Fraassen’s interpretation, will only describe for us what is observable.
In van Fraassen’s words:
“I use the adjective ‘constructive’ to indicate my view that scientific activity is one of construction rather than discovery: construction of models that must be adequate to the phenomena, and not discovery of truth concerning the unobservable” (p.5).
“We never have the option of accepting an all-encompassing theory, complete in every detail. So to accept one theory rather than another one involves also a commitment to a research programme, to continuing the dialogue with nature in the framework of one conceptual scheme rather than another. Even if two theories are empirically equivalent, and acceptance of a theory involves as belief only that it is empirically adequate, it may still make a great difference which one is accepted” (ibid).
We can contrast van Fraasen’s view with a naive statement of scientific realism, which is that “the picture which science gives us of the world is a true one, faithful in its details, and the entities postulated in science really exist: the advances of science are discoveries, not inventions” (p.6-7). This view provides an answer to the two questions mentioned above by telling us ‘what there is’ and that science is an enterprise of discovery. Van Fraassen puts the scientific realist position more firmly by defining it as: “Science aims to give us, in its theories, a literally true story of what the world is like: and acceptance of a scientific theory involves the belief that it is true” (p.8). With the definition and description of ‘constructive empiricism’ as well as ‘scientific realism’, we now have a basic idea of how they are oriented toward each other in relation to a theory’s relation to the world and what a scientific explanation entails.
Is scientific realism the better approach? Constructive Empiricism? Or perhaps some other view not mentioned yet? Is scientific activity one of ‘construction’ or of ‘discovery’? It should go without saying that these ideas are inquired into and developed in much greater depth for the remainder of the book.
Godfrey-Smith, Peter. 2003. Theory and Reality: An Introduction to the Philosophy of Science. Chicago, University of Chicago Press.
Van Fraassen, Bas. 1980. The Scientific Image. Oxford, Oxford University Press.