LA CIENCIA AYER Y HOY
Who is a theorist?
Eric Scerri Departament of Chemistry and Biochemistry. Univesrity of California. Los Angeles, USA. email@example.com [Recibido en mayo de 2011, aceptado en julio de 2011]
This article carefully analyzes a recent paper by Weisberg in which it is claimed that whenMendeleev discovered the periodic table he was not working as a modeler but instead as a theorist. I argue that Weisberg is mistaken in several respects and that the periodic table should be regarded as a classification, not as a theory. In the second part of the article an attempt is made to elevate the status of classifications by suggesting that they provide a form of ‘side-ways explanation’.Keywords: Law; Mendeleev; periodic table; theory; scientific explanation; scientific models.
Comments on Weisberg’s “Who is a modeler?”
In a paper published in 2007, Michael Weisberg sets out to answer the question of “who is a modeler?” (Weisberg, 2007). His study presents a contrast between the work of Volterra’s mathematical approach to the question of why there was an unusual shortage of fishin the Adriatic Sea shortly after the end of the First World War and Mendeleev’s discovery of the periodic system in 1869. Weisberg claims that Volterra’s work is a good example of scientific modeling and consequently that Volterra can definitely be said to be a modeler. Weisberg then considers Mendeleev’s discovery of the periodic system, and the subsequent use that Mendeleev made of hisdiscovery, in order to argue that this was not an example of scientific modeling. Rather than being a modeler, Weisberg claims that “…Mendeleev is a theorist”, contrary to the account provided by Shapere among others (Shapere, 1977). In my own response I will have little to say about Volterra except to agree with Weisberg’s assessment that this study was a good example of modeling. My critique will focuson the work of Mendeleev as described by Weisberg. Moreover, my concern will not be so much with whether or not Mendeleev was a modeler. It so happens that I also agree with Weisberg in denying that Mendeleev was acting as a modeler. My disagreement is with Weisberg’s claim that, rather than being a modeler, Mendeleev was functioning as a theorist and that his periodic system can be regarded as atheory rather than as a model. My own suggestion is that Mendeleev provided a classification rather than a model or theory. Before returning to expand on this suggestion I would like to analyze Weisberg’s statement about Mendeleev in some detail.
Weisberg writes, “Similarly, it has been argued that Mendeleev articulated an important classification system, but not atheory. For example, Shapere claimed that what Mendeleev discovered was an ordered domain and that ‘[o]rderings of domains are themselves suggestive of several different sorts of lines of further research’ but not themselves theories (Shapere , p. 534). I believe this view to be mistaken for several reasons. The first reason involves the remarkable predictions that Mendeleev was able to make onthe basis of his Periodic System” (Weisberg, 2007, p. 213).
Revista Eureka sobre Enseñanza y Divulgación de las Ciencias Universidad de Cádiz. APAC-Eureka. ISSN: 1697-011X DOI: http://hdl.handle.net/ http://reuredc.uca.es
WHO IS A THEORIST?
Weisberg continues by citing detailed evidence to show that three of Mendeleev’s predictions, those of gallium, scandium and germaniumwere especially accurate. Weisberg then writes, “Mendeleev’s predictions might look like trivial exercises, making inferences about missing ‘books on the shelf’ or filling empty slots. This underestimates the significance of the achievement: Mendeleev had no empirical knowledge that there were any empty slots to be filled” (Weisberg, 2007, p. 214). I want to begin by exploring this last...