This a pair of papers about the relation between 19th-century accounts of taxonomy and present debates about natural kinds.
The standard narrative makes two claims of continuity: first, that recent debates are continuations of ones that began with John Stuart Mill; second, that the element of Mill's system which maps onto our term natural kind is his term Kind. The first paper argues against the first claim of continuity, and the second against the second.
According to the standard narrative, natural kind is a technical notion that was introduced by John Stuart Mill in the 1840s and the recent craze for natural kinds, launched by Putnam and Kripke, is a continuation of that tradition. I argue that the standard narrative is mistaken. The Millian tradition of kinds was not particularly influential in the 20th-century, and the Putnam-Kripke revolution did not clearly engage with even the remnants that were left of it. The presently active tradition of natural kinds is less than half a century old. Recognizing this might help us better appreciate both Mill and natural kinds.
The accepted narrative treats John Stuart Mill's Kinds as the historical prototype for our natural kinds, but Mill actually employs two separate notions: Kinds and natural groups. Considering these, along with the accounts of Mill's 19th-century interlocutors, forces us to recognize two distinct questions. First, what marks a natural kind as worthy of inclusion in taxonomy? Second, what exists in the world that makes a category meet that criterion? Mill's two notions offer separate answers to the two questions: natural groups for taxonomy, and Kinds for ontology. This distinction is ignored in many contemporary debates about natural kinds and is obscured by the standard narrative which treats our natural kinds just as a development of Mill's Kinds.
An earlier version was presented at the 2014 Philosophy of Science Association meeting under the title 'What the 19th century knew about taxonomy and the 20th forgot'.
@ARTICLE(Magnus2014,
AUTHOR = {P.D. Magnus},
TITLE = {No grist for {M}ill on natural kinds},
JOURNAL = {Journal for the History of Analytical Philosophy},
YEAR = {2014},
VOLUME = {2},
NUMBER = {4},
PAGES = {1--15}
)
A draft of 'No grist for Mill on natural kinds' was first posted on-line 5nov2011.
@ARTICLE(Magnus2015,
AUTHOR = {P.D. Magnus},
TITLE = {John Stuart Mill on taxonomy and natural kinds},
JOURNAL = {HOPOS},
YEAR = {2015},
VOLUME = {5},
NUMBER = {2},
MONTH = {Fall},
PAGES = {269--280}
)
A draft of 'John Stuart Mill on taxonomy and natural kinds' was first posted on-line, under a different title, 25jun2013.