Knowl. Org. 38(2011)No.1 9 Forum: The Philosophy of Classification Forum: The Philosophy of Classification The Periodic Table and What is the Nature of the A Note on the Debate Between the Philosophy of Periodic Table as a Hjørland and Scerri on the Sig- Classification Classification System? nificance of the Periodic Table Birger Hjørland Eric Scerri John Dupré 1.0 Introduction: This debate I would like to thank Professor Birger I am very grateful to Professor Birger Hjørland for his generous review of my Hjørland for giving me the opportu- Thanks to Professor Eric Scerri for en- book on the periodic table of the ele- nity to comment on his exchange with gaging in debate in this journal (Scerri ments (Hjørland 2008). As he states, Professor Eric Scerri on the periodic 2011) by replying to my review (Hjør- the periodic table represents perhaps table of the elements. However, since land 2008a) of his book (Scerri 2007). the strongest claim for a natural classi- Hjørland himself has provided a de- One of my points has been that we in fication that one can find in any disci- tailed commentary on Scerri’s response our community (Knowledge Organiza- pline. As such it is worthy of the atten- to his (Hjørland’s) review of Scerri’s tion, KO / Library and Information tion of scholars of classification and book on the topic, and since I am not Science, LIS) have been too isolated knowledge organization in general. I in an expert on the philosophy of chemis- from broader academic fields related to turn wish to compliment Hjørland for try, I shall limit myself to a few com- classification and the organization of promoting this interdisciplinary activity ments on what Scerri says about my knowledge. The present debate is a via his review and many previous writ- own views. (In fact one paragraph in a step towards reversing this situation. ings on the subject. I think that there is two page article on scientific classifica- Strangely enough, at the end of his re- much that can be learned from taking tion, and one footnote from my 1993 ply, Scerri (2011) seems to question this debate a little further. book, The Disorder of Things, most of (even) this view. In this connection he I now turn to some specific re- which are quoted in the discussion to seems, however, to confuse two differ- sponses to his book review. Hjørland date, as far as I can recall exhaust my ent things: 1) I have never said that the claims that classification should be, and published writing specifically on the periodic system has not influenced is in fact, based on pragmatic criteria topic of the periodic table.) LIS-classifications. On the contrary, I and thereby insists that even in the Scerri suggests that I am guilty of mentioned in my review two examples case of the periodic table, classification circularity in assuming that chemists (MEDLINE and UDC) which are is pragmatic rather than ‘natural.’ He aim at a structural analysis of matter clearly influenced by the periodic sys- also claims that the classification of and then find a classification based on tem. 2) What I did say was that books knowledge can be carried out by using structural elements suits this purpose. such as Scerri’s―and the broader field one of four approaches that he identi- It seems to me that my assumption of the philosophy of classification―are fies as empiricism, rationalism, histori- might be false, but hardly justifies a mostly ignored by scholars in KO/LIS. cism and pragmatism, of which he be- charge of circularity. I am happy to de- That people in KO seem to consider lieves the last to be the most “advanced fer to Scerri’s far greater expertise if he themselves “the professionals” in clas- theory.” Hjørland concedes (2008, 253) tells me it is false. However, I cannot sification (cf. Beghtol 2003), but that that the periodic system is: “probably accept his claim that chemists aim for the relation to the philosophy of classi- one of the most difficult classification “the analysis of matter period.” I do fication—as well as to specific scien- systems to defend from a pragmatist not believe there could be any such tific classification research—needs to point of view,” but adds that: “it is also thing. Matter has an enormous range be strengthened (cf., Hjørland & Ni- important to test our views against the of properties: macrostructural proper- colaisen 2004 and Nicolaisen & Hjør- most pre-eminent classifications if our ties such as strength, elasticity or hard- land 2004). arguments should be convincing.” ness; nutritional and toxicological (continued next page column 1) (continued next page column 2) (continued next page column 3) 10 Knowl. Org. 38(2011)No.1 Forum: The Philosophy of Classification Scerri points out that Hulme (1911) He presents his first line of attack on properties; aesthetic properties; and so is outdated; I am not, however, sup- the notion that the periodic system on. If there is such a thing as “analysis porting Hulme’s view about the irrele- classifies the elements as natural kinds period” it is, as the Greek etymology vance of the periodic system (and the in the following way. Hjørland points suggests, the breaking down of things philosophy of classification); on the out that although there may only exist into parts. Of course, chemists might contrary, I disagree, like Scerri, with one periodic law, there have been over have found that there were no such Hulme on this point―it was just men- 700 periodic tables published, which parts, that all kinds of stuff were ho- tioned to underline my view about the depend upon the particular pragmatic mogeneous and unanalysable, in which critical attitude towards the philosophy interests of any designer. My response case they would have had to content of classification in KO. That Hulme’s to this point would be to shift the dis- themselves with a rather unilluminat- paper is very old is an illustration of cussion to the periodic law rather than ing natural cataloguing of stuffs. The how difficult it is to identify more re- periodic tables, which as I am sure point is that there are many different cent discussions about the periodic Hjørland recognizes are attempts to enquiries that could be launched about system in the literature of KO. Hulme capture the more abstract periodic law. matter, and chemists are interested in was also named because he is known I do not believe that the failure of matter from a specific, perhaps funda- for the important principle of literary chemists to arrive at one commonly mental in some sense, perspective. warrant in KO and as the founder of agreed table, or representation, should This is the point about jade—not statistical bibliography, which is now be taken to mean that the elements that chemists don’t distinguish jadeite known as bibliometrics. themselves are not natural kinds or and nephrite, but that from another If Scerri wishes to prove me wrong that periodic classification is inherently perfectly respectable perspective they on this point, a proper argument would of a pragmatic nature. It may just be need not be distinguished, thus show- be to point to more recent texts and to that the current attempts at representa- ing that the perspective of chemistry is demonstrate how writings about the tion are infused with pragmatism since not the only one possible on matter. periodic system, about other scientific individual chemists may indeed be in- If gemology seems too unscientific classifications and about the philoso- terested in putting the periodic table to an activity to be relevant, one need only phy of classification have influenced particular uses rather than arriving at look to geology for classifications of theory and writings in KO and LIS one correct representation that reflects material stuff that follow a different (e.g., checking citations in LIS to this a natural classification. It is rather to path from those in chemistry. The min- To say that a kind is natural is More philosophically speaking, “It is a classification system to say that it corresponds to a the identity and properties of which, once discovered, seems grouping or ordering that does any class of entities are some- inevitable.” not depend on humans. what separate issues eral olivine, one of the commonest sub- literature, e.g., by using Web of Science). the philosophy of chemistry, I suggest, stances on Earth, constituting a major I do not believe Scerri knows the litera- that one should look for the more gen- part of the Earth’s upper mantle, is re- ture of KO/LIS and that his denial of eral nature of the periodic law and the ferred to by the chemical formula my claim about the neglect of the lar- periodic table (Scerri 2009). (Mg,Fe)2SiO4. The parenthetical part of ger field of classification research in Hjørland turns to denying that ele- this formula indicates that olivine is a KO is valid. Much more relevant is ments are natural kinds more directly variable mixture of forsterite (Mg2Si Scerri’s view about the nature of the and quotes a recent book by Bryant as O4) and fayalite (Fe2SiO4). Of course periodic system (or periodic systems) a source of support. Bryant (2001, 88) one can describe the chemical composi- and the implications for the theory of writes: “even in the case of chemical tion of olivine; I have just done so. But classification, which are considered be- elements more than one kind of causal the reason that there olivine is a signifi- low.