Philosophical Elements in Thomas Kuhn’s Historiography of Science * Paul HOYNINGEN -HUENE Received: 7.5.2012 Final version: 30.7.2012 BIBLID [0495-4548 (2012) 27: 75; pp. 281-292] ABSTRACT: To begin, the so-called ‘selectivity of historical judgment’ is discussed. According to it, writing history requires a comparative criterion of historical relevance. This criterion contains philosophical elements. In Kuhn’s case, the criterion directs historical research and presentation away from Whiggish historiography by postulating a hermeneutic reading of historical sources. This postulate implies some sort of internalism, some sort of rationality of scientific development, and historical realism. To conclude, some consequences of Kuhn’s anti-Whiggism are discussed. Keywords: Historical relevance; Anti-Whiggism; internalism; rationality of science; historical realism. RESUMEN: Para empezar, se discute la llamada “selectividad del juicio histórico”. De acuerdo con ello, escribir histo- ria requiere un criterio comparativo de relevancia histórica. Este criterio contiene elementos filosóficos. En el caso de Kuhn, el criterio aleja la investigación y la presentación histórica de la historiografía Whig al pos- tular una lectura hermenéutica de las fuentes históricas. Este postulado implica alguna clase de internismo, de racionalidad del desarrollo científico y realismo histórico. Para concluir, se discuten algunas consecuen- cias de la postura anti-Whig de Kuhn. Palabras clave: Relevancia histórica; postura anti-Whig; internismo; racionalidad de la ciencia; realismo histórico. 1. Introduction For reasons that have a long and indeed plausible history, historians of science as his- torians are often not particularly interested in what philosophers have had to say about science and its history. This is nicely illustrated by what Thomas Kuhn said in the late 60s about his interactions with Carl Gustav Hempel: No one in recent years has done so much to clarify and deepen my consideration of philosophi- cal problems as my Princeton colleague C. G. Hempel. But my discourse with him and my ac- quaintance with his work does nothing for me at all when I work on, say, the history of thermo- dynamics or of the quantum theory. (Kuhn 1977a, ET , 12) Thus, when I discuss philosophical elements in some particular form of historiog- raphy, I had better have persuasive reasons for why this topic might also be interesting for historians. In an attempt to provide such reasons, I shall start with a rather strong claim; namely, that no historiography, including the historiography of science, can be entirely philosophically innocent. The assertion is, in other words, that all historiog- raphy depends on and makes use of philosophical elements. The formulation that his- toriography “depends on and makes use of” philosophical elements may already be misleading, and I will come back to it later in this paper. But first, I shall defend my claim in general in the next section. In section 3, I will fill out these abstract considera- * I wish to thank Bettina Heintz and two anonymous referees for critical remarks on an earlier version of this paper, and Eric Oberheim for linguistic improvements. THEORIA 75 (2012): 281-292 282 Paul HOYNINGEN -HUENE tion with some Kuhnian flesh. In section 4, I will develop the philosophical elements that are inherent in Kuhn’s mode of doing history of science. In the final section, I will briefly discuss some systematic limits of anti-Whiggism. 2. The necessity of criteria of historical relevance for historiography The fact from which I begin has many names. It has been called “the selectivity of his- torical judgment” and it has been described by the slogan: “In history, there is no de- mocracy of facts”. Kuhn spoke about “preconceptions about what is essential, what is not” and of “selective principles” of historiography (Kuhn 1971, 138, 142; also 1977a, ET , 14, 18). I shall use a more elaborate description which reads: Both in research and in presentation, all historiography needs comparative criteria of historical relevance . Such cri- teria are indispensable on the grounds that some decision must be made as to what belongs in a given historical narrative and what does not. The criteria must be com- parative in that they allow for distinguishing degrees of importance. Stories may be told more or less comprehensively. Shorter versions need not omit essentials; neither must longer versions incorporate inessentials. Let me illustrate immediately. It has been estimated that in the comprehensive histories of all of natural science, something like 1 in 300 scientists who worked at a given time is mentioned (Graf-Stuhlhofer 1995). Of course in histories with higher disciplinary resolution, the percentage is much higher. Yet, the fact remains that not every scientist is mentioned along with everything he or she did. The reason is quite clear. A historical narrative is not, cannot, and should not be a 1:1 replica of the respective historical episode. Only the “im- portant” figures and facts should be part of the story, and above I have called that im- portance “historical relevance”. The varying degree of historical relevance cannot only be seen in the final narrative, but also in the research that precedes it. It governs what is investigated and what is not for a given project. It governs whether or not to rebuild an apparatus or re-perform a historical experiment. To illustrate again: If a priori in- sights are the main ingredient in superb science, then the question about what may have been the outcome of some experiment in the real world is not so important. If, however, empirical data play a pre-eminent role, then one may try to recreate a partic- ular historical experimental situation. I am here alluding to the tension between Koyré and Settle with respect to Galileo (see, e.g., Brush 1995, 228). It may be useful to distinguish different sorts of historical relevance (see Hoyning- en-Huene 1993, 13-14). I think that there are roughly three sorts, but they overlap and interrelate. This latter fact is, however, not important in our context. The first sort of historical relevance is factual relevance . It selects material which is relevant in order for the history of a given topic to be told at all. Thus, talking about the history of special relativity necessarily involves some talk about electrodynamics. The second sort of his- torical relevance is narrative relevance . It selects for material which must be taken into account if the resulting text is to be a proper narrative. Such material includes those facts by which a historical report gains the narrative continuity that it needs (see Kuhn 1977a, ET , 8-9) or facts which make plausible what would otherwise be implausible. For example, take the delay in the start of an airplane caused by heavy snowfall which allowed two physicists from diverse areas talk to each other for several hours. If this, Theoria 75 (2012): 281-292 Philosophical Elements in Thomas Kuhn’s Historiography of Science 283 in turn, led to deep innovations in one of their fields, then in order for the story of this field to be adequately told, this consequential incident must be included. The final sort of historical relevance is pragmatic relevance . It selects for material without which the pragmatic goal of a historical narrative cannot be realized. Thus, the content of a historical narrative is determined partly by the audience to which it is addressed, and partly by the effect it is meant to have on this audience. A narrative aimed at deepen- ing the understanding of today’s genetics may be different from one aimed at under- standing some historical episode in genetics solely in its own time and in its own terms. Here, I am alluding to the difference between today’s mainstream history of science and, for example, Ernst Mayr’s concept of developmental history (see Mayr 1990). Some of the elements of these sorts of historical relevance can properly be called philosophical elements of the respective historiographic work. By this I mean, roughly and very generally put, the usually implicit assumptions about history itself, or about prop- er historical research and presentation which influence historical work. It is clear that, for example, decisions about the general aims of historiography of science (which I just mentioned in the genetics example), or convictions about the influence of social factors on the content of science, qualify both as criteria of historical relevance and as philosophical elements of the respective historiography. I hope it is clear by now that historical work cannot proceed without them. Trying to avoid them in history is as il- lusory as the absolutely theory-free facts which the positivists sought as the epistemic basis of science. Although it is not part of the main line of this paper’s argument, at this point I want to insert a remark about the possibility of drawing philosophical lessons about science from studying its history. Many people have the impression that from the his- tory of science, very little or even nothing philosophical about science can be gleaned for methodological reasons. But that was exactly what Kuhn tried to do. He tried to extract philosophical lessons about science from its history. One of the plausible rea- sons for why nothing of philosophical interest could possibly be extracted from the historical narratives about science would be that all that one could gain would be just those philosophical elements which one had plugged into the history oneself, in the form of comparative criteria of historical relevance. Kuhn saw this as a danger for Lakatos’ program of an evaluation of methodological positions through history, given Lakatos’ conception of internal history (Kuhn 1971, 140-143). But as in science, where theory-laden data do not lose their potential to challenge theories (even the very same theories by which they are impregnated), philosophical elements embodied in the cri- teria of historical relevance do not rule out the possibility that historical narratives can challenge philosophical conceptions of science.