Philosophical Divides: a little story

Picture the following.  Camps of philosophers cordon themselves off from one another by drawing lines in the still sands of a breezeless desert.  There they entrench, staring each other down from opposite sides of the line for a decade or two.  Eventually they tire of looking across the divide, and so begin to fraternize with only those philosophers in their proximity.  Later they forget about the philosophers on the other side of the line, and when the occasional hawkeyed upstart or pesky defector announces the existence of a whole country of philosophers not too far away, they retort that those on the other side of the line are not ‘real’ philosophers.  They are, the upstart and the defector are told, philosophical poseurs at best, or philosophical perverts at worst.  The language that is used, in fact, is exactly that contemptuous and contentious.