2012 年 40 巻 1 号 p. 9-25
"The death of essentialism" has been widely accepted in biology and philosophy of biology for more than half a century, but recently essentialism seems to raise its head again. The purpose of this paper is to criticize one particular type of "new essentialism" called the homeostatic property cluster view of the species category. According to this view, there is the causal entanglement of properties that creates the biological units recognized as species. However, there is a significant biological phenomenon called lateral gene transfer, which undoes the entanglement, especially in microorganisms. Thus, I conclude that the view is untenable in light of our current biological knowledge, including microbiological one. In addition, I consider the reasons why we should reject species eliminativism even if we accept anti-essentialism and species pluralism.