Why do we name organisms? Some reminders from the past

The naming systems of Linnaeus and Bentham in particular are examined to clarify the relationships between naming and ideas of relationships. Linnaean binomials were adopted largely for practical reasons. Furthermore, Linnaeus proposed his names in the context of system, putting organisms in groups of 10. This allowed botanists of moderate capabilities to know at least the genera. Although binomials are names of taxa of the two lowest levels of a rank hierarchy, much of Linnaeus’ work does not fit easily in the currently widely accepted view of Linnaeus as a hard-bitten essentialist. Neither Lamarck nor the later Bentham believed in a rank hierarchy, although to name organisms both used what is here called a flagged hierarchy: name terminations indicating only a set of inclusion relationships, not ranks of nature implied by a rank hierarchy. Bentham was clear that the adoption of a flagged hierarchy with groups of a particular size in the Genera plantarum was to facilitate botanists’ understanding of the system as a whole. Systematists like Bentham and Linnaeus managed information and presented classification systems simultaneously. I conclude that the lower level of Linnaeus’ hierarchy is a special case of the noun + adjective combination that pervade folk classifications in particular and human language in general. Linking essentialism and “Linnaean” nomenclature is at best a red herring, thus few nineteenth-century botanists believed in a fully-developed rank hierarchy. Naming hierarchies are mostly such that at each level members belong to only one group, and this is at a higher level; most such hierarchies are fairly shallow. Historically, uninomials have seemed more attractive when generic limits were in flux, but suboptimal when relationships were more stable. Naming systems in general incorporate a substantial element of convention, emphasizing particular numbers of groups and groups of particular size; this facilitates comprehension and communication. Similar conventions will be needed whatever naming system is used.