The Advancement of Science

"For me, this book has a personal significance. I was given a copy of it in August 1993 by my then thesis supervisor David Papineau , while I was writing up my doctoral dissertation. David advised me not to read it until I submitted my dissertation so that I wouldn’t get distracted. I followed his advice and read it in the beginning of 1994. It was a revelation for me. The book aims to deflate the “legend” that science is a march to truth (to the one complete true story of the world) and that this is achieved by the use of a fully objective scientific method. Many critics of science in the twentieth century, from Thomas Kuhn to the social constructivists, have taken the failures of the legend to show that science cannot reveal truths about the world, or to question its objectivity, rationality and hegemony. But Kitcher does not want to do this. In his book, he aims to show how scientific progress and objectivity can still be defended, even though the legend is just a legend. “Many critics of science in the twentieth century, from Thomas Kuhn to the social constructivists, have taken the failures of the legend to show that science cannot reveal truths about the world” This is done within a thoroughly naturalistic framework in which scientists are seen, not as sole knowers, but as biological and social beings with various cognitive constraints and limitations. Individual cognitive practices are integrated into a network of collective consensus-forming practices. One such practice aims to offer cogent unifying explanations of the worldly phenomena, where the unification consists in using the same explanatory schemata to account for diverse phenomena, like Darwin did with his explanatory pattern of natural selection. Scientific enterprise is progressive in that more and more significant truths about the world are discovered and by making more and more refined classifications of natural kinds. The two major challenges to scientific objectivity have come from the Kuhnian notion of incommensurability and the social constructivist programme in the sociology of scientific knowledge. The notion of incommensurability was introduced by Kuhn to capture the relation between scientific paradigms before and after a scientific revolution. The pre-revolutionary and the post-revolutionary paradigms were said to be incommensurable in that there was no strict translation of the terms and predicates of the old paradigm into those of the new. Though Kuhn developed this notion in several distinct ways, its core is captured by the thought that two theories are incommensurable if there is no language into which both theories can be translated without residue or loss. Kuhn supplemented this notion of untranslatability with the notion of lexical structure : two theories are incommensurable if their lexical structures (that is, their taxonomies of natural kinds) cannot be mapped into each other. Too many philosophers, this notion threatened scientific objectivity since competing paradigms cannot be properly compared. Hence, there is no objective sense in which the new paradigm can be said to be more progressive than the old. Kuhn went to extremes by claiming that: The proponents of competing paradigms practice their trades in different worlds . . . Practicing in different worlds, the two groups of scientists see different things when they look from the same point of view in the same direction. This made the world well lost. To be sure, it’s best if we see Kuhn’s philosophy as a version of neo-Kantianism because it implied a distinction between the world-in-itself, which is epistemically inaccessible to inquirers, and the phenomenal world, which is constituted by the concepts and categories of the inquirers, and is therefore epistemically accessible to them. But Kuhn’s neo-Kantianism was relativised : he thought that there was a plurality of phenomenal worlds, each being dependent on, or constituted by, some community’s paradigm. The paradigm imposes, so to speak, a structure on the world of appearances: it carves up this world in ‘natural kinds’. This is how a phenomenal world is ‘created’. But different paradigms carve up the world of appearances into different networks of natural kinds. The second challenge was based on the so-called ‘symmetry principle’ in the ‘Strong Programme of the Sociology of Scientific Knowledge’ (SSK). This programme aimed at a causal-naturalistic explanation of scientific belief and the claim was that, as David Bloor put it, the same types of cause would explain true and false, or rational and irrational, beliefs. Accordingly, the world drops out as a factor for the explanation of scientific belief. For the advocates of SSK, there are only locally credible reasons, and not “absolute proofs”, that one scientific theory is better than another. But, of course, scientists do not talk about “absolute proofs” of theories. Still, there are typically good evidential reasons to prefer one theory to another. In the extreme case of social constructivist views, the claim is that scientific entities are constructed by means of negotiations and other socially influenced consensus-making processes among scientists. Science is taken to be only one of any number of possible “discourses”, none of which is fundamentally truer than any other. What unites this cluster of views are vague slogans such as ‘scientific truth is a matter of social authority’ or ‘nature plays (little or) no role in how science works’. Kitcher clearly accepts that scientists are social beings and that there are a number of social influences on their views and work. However, he defends the view that the various social influences and biases are not so powerful that they prevent scientists from abandoning false beliefs and accepting truer ones. In other words, the social influences are seldom so powerful as to render negligible the reality’s contribution to scientific belief. For Kitcher, there is conceptual, explanatory and cognitive progress as science grows. He argues that there is no significant incommensurability between competing theories, since for him, scientific expression-types are no longer associated with single (putative) referents. Instead, each expression-type is endowed with a reference potential: a potential such that its tokens may refer to more than one (putative) entity, depending on the event that has initiated the production of each particular token. This allows him to speak of reference-preserving translation between competing theories. For instance, Joseph Priestley’s “dephlogisticated air” has in its reference potential both phlogiston-free air and oxygen. Depending on the context of utterance, tokens of “dephlogisticated air” may refer to either of the two members of the reference-potential; hence, they may fail to refer altogether or fail to refer to oxygen . For Kitcher, conceptual progress is refinement of the reference-potential of concepts. Besides, unlike Kuhn, Kitcher thinks that there is considerable progress towards a truer account of the world. Even if our perception of nature may be theory-dependent, it does not follow that nature itself is theory-dependent."