Discussion: Rank Free taxonomy, and "species" (Mishler):
This will be a free-flowing and no doubt controversial discussion about rank-free classification in general, the Phylocode, and what to do about terminal taxa, i.e., "species"
Here is a short essay to set the stage; please read ahead of time : 
Getting Rid of Species.pdf
The reference is:
B.D. Mishler. 1999. Getting rid of species? In R. Wilson (ed.), Species: New Interdisciplinary Essays, pp.307-315. MIT Press.
