I'm sorry, I don't understand what you mean. By "Cartesian skeptic" do you mean a Cartesian dualist who is skeptical of pure materialism? Or a Cartesian skeptic who does not wish to rely on his senses, who is skeptical of scientific inquiry into objective reality? Or something else?
Someone who doesn't believe his sense inputs necessarily reflect any reality.
Here's the new thread for posting quotes, with the usual rules: