Scientific progress remains one of the most significant issues in the philosophy of science today. This is not only because of the intrinsic importance of the topic, but also because of its immense difficulty. In what sense exactly does science makes progress, and how is it that scientists are apparently able to achieve it better than people in other realms of human intellectual endeavour? Neither philosophers nor scientists themselves have been able to answer these questions to general satisfaction.

Scientific progress remains one of the most significant issues in the philosophy of science today. This is not only because of the intrinsic importance of the topic, but also because of its immense difficulty. In what sense exactly does science makes progress, and how is it that scientists are apparently able to achieve it better than people in other realms of human intellectual endeavour? Neither philosophers nor scientists themselves have been able to answer these questions to general satisfaction.

In the broadest sense of the phrase, there is action at a distance whenever there is a spatial or temporal gap (or both) between a cause and its effect. In this sense, it is not at all controversial that there is action at a distance. To cite a few instances: the page a few inches in front of you is impinging on your senses; the Sun is now warming the Earth; we are still living with the consequences of the Second World War. What is controversial is the idea of unmediated action at a distance, where there is both a gap between cause and effect and no intermediate causes and effects to fill it. The three examples just mentioned are cases of action at a distance, certainly, but not, surely, unmediated action at a distance. What we expect to find, in each case, is a spatially and temporally continuous causal series stretching across time and space.

The Research Assessment Exercise (henceforth abbreviated to RAE) was introduced in 1986 by Thatcher, and was continued by Blair. So it has now been running for 21 years. During this time, the rules governing the RAE have changed considerably, and the interval between successive RAEs has also varied. These changes are not of great importance as far as the argument of this paper is concerned. We will concentrate on the main features of the RAE which can be summarised as follows.

In the broadest sense of the phrase, there is action at a distance whenever there is a spatial or temporal gap (or both) between a cause and its effect. In this sense, it is not at all controversial that there is action at a distance. To cite a few instances: the page a few inches in front of you is impinging on your senses; the Sun is now warming the Earth; we are still living with the consequences of the Second World War. What is controversial is the idea of unmediated action at a distance, where there is both a gap between cause and effect and no intermediate causes and effects to fill it. The three examples just mentioned are cases of action at a distance, certainly, but not, surely, unmediated action at a distance. What we expect to find, in each case, is a spatially and temporally continuous causal series stretching across time and space.

Astronomers study the behaviour of the stars; philosophers of science study the behaviour of the astronomers. Philosophers of science, alongside historians and sociologists of science, are in the business of accounting for how science works and what it achieves. There is more to the philosophy of science than principled descriptions of scientific activity, since there are also all the normative questions of justification and warrant, but the descriptive task is an important part of the discipline and the primary focus of the present essay.

The aim of this paper will be to show that certain strongly realist forms of scientific realism are either misguided or misnamed. I will argue that, in the case of a range of robustly realist formulations of scientific realism, the ‘scientific’ and the ‘realism’ are in significant philosophical and methodological conflict with each other; in particular, that there is a tension between the actual subject matter and methods of science on the one hand, and the realists' metaphysical claims about which categories of entities the world contains on the other.

The Research Assessment Exercise (henceforth abbreviated to RAE) was introduced in 1986 by Thatcher, and was continued by Blair. So it has now been running for 21 years. During this time, the rules governing the RAE have changed considerably, and the interval between successive RAEs has also varied. These changes are not of great importance as far as the argument of this paper is concerned. We will concentrate on the main features of the RAE which can be summarised as follows.

What is it reasonable to believe about our most successful scientific theories such as the general theory of relativity or quantum mechanics? That they are true, or at any rate approximately true? Or only that they successfully ‘save the phenomena’, by being ‘empirically adequate’? In earlier work I explored the attractions of a view called Structural Scientific Realism (hereafter: SSR). This holds that it is reasonable to believe that our successful theories are (approximately) structurally correct (and also that this is the strongest epistemic claim about them that it is reasonable to make). In the first part of this paper I shall explain in some detail what this thesis means and outline the reasons why it seems attractive. The second section outlines a number of criticisms that have none the less been brought against SSR in the recent (and as we shall see, in some cases, not so recent) literature; and the third and final section argues that, despite the fact that these criticisms might seem initially deeply troubling (or worse), the position remains viable.

Let's begin with an old example. In De Rerum Naturua, Lucretius presented a thought experiment to show that space is infinite. We imagine ourselves near the alleged edge of space; we throw a spear; we see it either sail through the ‘edge’ or we see it bounce back. In the former case the ‘edge’ isn't the edge, after all. In the latter case, there must be something beyond the ‘edge’ that repelled the spear. Either way, the ‘edge’ isn't really an edge of space, after all. So space is infinite.

Astronomers study the behaviour of the stars; philosophers of science study the behaviour of the astronomers. Philosophers of science, alongside historians and sociologists of science, are in the business of accounting for how science works and what it achieves. There is more to the philosophy of science than principled descriptions of scientific activity, since there are also all the normative questions of justification and warrant, but the descriptive task is an important part of the discipline and the primary focus of the present essay.

According to logical positivism, so the story goes, metaphysical questions are meaningless, since they do not admit of empirical confirmation or refutation. However, the logical positivists did not in fact reject as meaningless all questions about for example, the structure of space and time. Rather, key figures such as Reichenbach and Schlick believed that scientific theories often presupposed a conceptual framework that was not itself empirically testable, but which was required for the theory as a whole to be empirically testable. For example, the theory of Special Relativity relies upon the simultaneity convention introduced by Einstein that assumes that the one-way speed of light is the same in all directions of space. Hence, the logical positivists accepted an a priori component to physical theories. However, they denied that this a priori component is necessarily true. Whereas for Kant, metaphysics is the a priori science of the necessary structure of rational thought about reality (rather than about things in themselves), the logical positivists were forced by the history of science to accept that the a priori structure of theories could change. Hence, they defended a notion of what Michael Friedman (1999) calls the ‘relativised’ or the ‘constitutive’ a priori. Carnap and Reichenbach held that such an a priori framework was conventional, whereas Schlick seems to have been more of a realist and held that the overall relative simplicity of different theories could count as evidence for their truth, notwithstanding the fact that some parts of them are not directly testable. All this is part of the story of how the verification principle came to be abandoned, and how logical positivism transmuted into logical empiricism.

The rosy dawn of my title refers to that optimistic time when the logical concept of a natural kind originated in Victorian England. The scholastic twilight refers to the present state of affairs. I devote more space to dawn than twilight, because one basic problem was there from the start, and by now those origins have been forgotten. Philosophers have learned many things about classification from the tradition of natural kinds. But now it is in disarray and is unlikely to be put back together again. My argument is less founded on objections to the numerous theories now in circulation, than on the sheer proliferation of incompatible views. There no longer exists what Bertrand Russell called ‘the doctrine of natural kinds’—one doctrine. Instead we have a slew of distinct analyses directed at unrelated projects.

The aim of this paper will be to show that certain strongly realist forms of scientific realism are either misguided or misnamed. I will argue that, in the case of a range of robustly realist formulations of scientific realism, the ‘scientific’ and the ‘realism’ are in significant philosophical and methodological conflict with each other; in particular, that there is a tension between the actual subject matter and methods of science on the one hand, and the realists' metaphysical claims about which categories of entities the world contains on the other.

There is a well-worn example—well worn in some circles, anyway—of what you might think of as racist bridges. Robert Moses, the celebrated New York architect, designed unusually low bridges over the roads from Long Island to Jones Beach. The bridges were designed in this way so as to prevent the poor and predominantly black locals from travelling to the beach by bus—the affluent, white car owners can slip under them with ease. The bridges prevent certain members of the community from enjoying the beach as surely as a phalanx of clansmen. Perhaps the strongest moral drawn from the story is the claim that the bridges are political. The objects themselves are imbued with dubious values.

In a short 1997 book entitled Simplicity as Evidence of Truth, the Oxford philosopher Richard Swinburne has put forward the following thesis summarily: ‘… for theories (of equal scope) rendering equally probable our observational data (which, for brevity I shall call equally good at “predicting”), fitting equally well with background knowledge, the simplest is most probably true’.