Did Reason Evolve as a Persuasion Tool?
http://www.schneier.com/blog/archives/2011/06/did_reason_evol.html
The beauty of the internet is that I can usually just quote my thoughts from the comments: “…reasoning was really a branch of rhetoric until Socrates and/or Plato started pretending otherwise.”
I have a blog in draft that uses the awkward adoption of the trivium into modern quadrivium as a snide aside.