How did the political right and the left come to be?

How have certain ideologies become associated with the right and the left, and for that matter, how did the terms “right and left” originate to differenciate between ideologies?

BTW, if this becomes inconclusive, I’ll just ask the master.

The French post revolutionary assembly, I believe: it describes the Speaker’s point of view regarding where the various political groupings sat.

Too late. Somebody already asked him. http://www.straightdope.com/classics/a3_321.html

Well, I got my answer, I guess. I was kind of hoping for a long debate though.

OK, new question. Why did the French national assembly of 1789 pick this certain layout of seating?