Type specimens are used to designate species. What is the nature of the relation between a type specimen and the species it designates? If species names are rigid designators, and type specimens ostensively define species, then that relation is, at the very least, a close one. Levine :325–338, 2001) argues that the relationship of type specimen to a named species is one of necessity—and that this presents problems for the individuality thesis. Namely, it seems odd that a contingently selected specimen (...) should belong to a species of necessity. In considering Levine’s argument, LaPorte suggests that recognizing the distinction between de re and de dicto necessity resolves Levine’s worries. I reconsider the motivating question: does a type specimen belong of necessity to the species that it designates? In light of taxonomic cases and practice the answer is clear: definitively not. This is particularly clear in the case of re-designation of types by taxonomic decree. I explain how this helps reveal how taxonomists prioritize competing theoretical commitments, and offer a defense of the individuality thesis as applied to these particular cases. In short, I demonstrate how to misidentify a type specimen. (shrink)

Some plausibly necessary a posteriori theoretical claims include ‘water is H 2 O’, ‘gold is the element with atomic number 79’, and ‘cats are animals’. In this paper I challenge the necessity of the third claim. I argue that there are possible worlds in which cats exist, but are not animals. Under any of the species concepts currently accepted in biology, organisms do not belong essentially to their species. This is equally true of their ancestors. In phylogenetic systematics, monophyletic clades (...) such as the animal kingdom are composed of an ancestral stem species and all of its descendants. If the stem species had not existed, neither would the clade. Thus it could have been the case that all the organisms which actually belong to the animal kingdom might have existed yet not have been animals. (shrink)

The longstanding species problem in biology has a history that suggests a solution, and that history is not the received history found in many texts written by biologists or philosophers. The notion of species as the division into subordinate groups of any generic predicate was the staple of logic from Aristotle through the middle ages until quite recently. However, the biological species concept during the same period was at first subtly and then overtly different. Unlike the logic sense, which relied (...) on definitions of the essence of both genus and species, biological species from the time of Epicurus were consistently considered to involve a reproductive element: in short, living species relied not on essential definitions, but on the generative cause, which might not be definable. I term this the generative conception of species: species were the generation by reproduction of form. This undercuts the claim that species before Darwin were essentialist, and divorces the notion of a type from that of essence. In fact, as late as the end of the nineteenth century, logicians explicitly treated biological “species” as a homonym only of logical essentialist species, and permitted considerable deviation from the type or form. At every point, species in logic were thought to be a subset, in effect, of some more general notion. I sketch a history of both philosophical and biological traditions of the species concept, before turning to the current conceptions. These are reconsidered in the light of this history, and in particular Mayr’s changing views are shown to be somewhat Whiggish, historiographically. Of the many touted biological species concepts, only one of which (Mayr’s) is called _the_ Biological Species Concept, none appears to capture all the relevant facts, intuitions, and operational requirements of biology. Cladistic conceptions, however, have much in common with the older philosophical literature, in that the natural group of cladism is the clade, or monophyletic group. After considering the Individuality Thesis, and the metaphysics of species, we see that species are the most particular terminal taxa in a clade, and that they are “defined” in terms of the particular synapomorphies, or evolved characters, that are causally responsible for keeping the lineages that organisms form distinct from one another. In this way, we can remain within the generative conception of species that has been in play for over two millennia, and yet avoid the pitfalls of prior attempts to find a universal conception of species. (shrink)

Linnaean-style, rank-based codes of taxonomic nomenclature provide stability to the relation between taxon names and their referents through the device of nomenclatural types. The practice of using types to tether names to taxa is uncontroversial and well-understood. But the nature of the relation between types, names, and taxa continues to be a topic of philosophical debate. A particularly contested issue is whether it is necessary for taxa that have a type specimen to contain their type specimen. Jerzy Brzozowski has recently (...) offered a novel account of taxon names that, he claims, shows that the relation between a type specimen and the (sub)species it belongs to is contingent (Brzozowski in Hist Philos Life Sci 42(3):1–25, 2020). I argue that this is mistaken. While Brzozowski’s contribution helps to advance the debate by bringing concepts from the philosophy of reference to bear on taxonomic naming practices, his new account of taxon names fails to support his central argument. Indeed, I show that the philosophical concepts he introduces into the debate cement the view that it is necessary for a (sub)species with a type specimen to contain it. (shrink)

A few philosophers of biology have recently explicitly rejected Essential Membership, the doctrine that if an individual organism belongs to a taxon, particularly a species, it does so essentially. But philosophers of biology have not addressed the broader issue, much discussed by metaphysicians on the basis of modal intuitions, of what is essential to the organism. In this paper, I address that issue from a biological basis, arguing for the Kripkean view that an organism has a partly intrinsic, partly historical, (...) essence. The arguments appeal to the demands of biological explanation and are analogous to arguments that I have given elsewhere that a taxon has a partly intrinsic, partly historical, essence. These conclusions about the essences of individuals and taxa yield an argument for Essential Membership. Finally, I cast doubt on LaPorte’s objection to that doctrine arising from the view that a species cannot survive having a daughter. (shrink)

Biological taxonomists rely on the so-called ‘type method’ to regulate taxonomic nomenclature. For each newfound taxon, they lay down a ‘type specimen’ that carries with it the name of the taxon it belongs to. Even if a taxon’s circumscription is unknown and/or subject to change, it remains a necessary truth that the taxon’s type specimen falls within its boundaries. Philosophers have noted some time ago that this naming practice is in line with the causal theory of reference and its central (...) notion of rigid designation: a type specimen fixes the reference of a taxon name without defining it. Recently, however, this consensus has come under pressure in the pages of this journal. In a series of articles by Alex Levine, Joseph LaPorte, and Matthew Haber, it has been argued that type specimens belong only contingently to their species, and that this may bode problems for the relation between type method and causal theory. I will argue that this ‘contingency debate’ is a debate gone wrong, and that none of the arguments in defense of contingency withstand scrutiny. Taxonomic naming is not out of step with the causal theory, but conforms to it. However, I will also argue that this observation is itself in need of further explanation, since application of the type method in taxonomic practice is plagued by errors and ambiguities that threaten it with breaking down. Thus, the real question becomes why taxonomic naming conforms to the causal theory in the first place. I will show that the answer lies in the embedding of the type method into elaborate codes of nomenclature. (shrink)

The object of this paper is to suggest how the Frege–Dummettian notions of criterion of identity and criterion of application can be put to work within Putnam’s account of reference for natural kind terms in “Meaning of ‘Meaning’ ”. By doing so, some light can be shed on Putnam’s earlier views on “necessity relative to a body of knowledge” as well as his later views on sortal identity. If the Frege–Dummettian criteria are indeed at work within Putnam’s account, then we (...) must either give up rigidity or else give up the division of linguistic labor hypothesis. I will give an example from biological nomenclature that may sway us towards giving up the former. (shrink)

The so-called ‘type method’ widely employed in biological taxonomy is often seen as conforming to the causal-historical theory of reference. In this paper, I argue for an alternative account of reference for biological nomenclature in which taxon names are understood as descriptive names. A descriptive name, as the concept came to be known from the work of Gareth Evans, is a referring expression introduced by a definite description. There are three main differences between the DN and the causal account. First, (...) according to the DN account, rather than fixing a name to a referent, the assignment of a type specimen to serve as the name-bearer for a taxon should be seen as performatively establishing a synonymy between a name and a definite description of the form “the taxon whose type is t”. Each taxon name is therefore associated with a criterion of application, a semantic rule that establishes the connection between the name and the descriptive content. This is the second major difference from the causal account: taxon names do have some descriptive content associated with them. The final locus of dissent concerns the strength of the modality resulting from the usage of taxon names. In order to address this point, I use the DN account to focus on the debate between Matt Haber and Joeri Witteveen concerning misidentification of type specimens, misapplication of names, and the truth conditions of Joseph LaPorte’s de dicto necessary sentence “Necessarily, any species with a type specimen contains its type specimen”. Using a pragmatic variant of the distinction between attributive and referential uses of descriptions, I argue that a metalinguistic version of the de dicto sentence is in fact falsified, as previously argued by Haber. (shrink)

The Possibility of Inquiry: Meno’s Paradox from Socrates to Sextus, by FineGail. Oxford: Oxford University Press, 2014. Pp. xiv + 399.