Twenty years, a French chef told me that what defines a bisque is that it is a thick pureed soup thickened with rice. He said that over the years a lot of people had taken liberties with the term bisque, but the definition he gave me he said was taken from Escoffier. I had no reason to question him and have believed it to this day. Somewhat in suppport, here is a blurb from an article in Art Culinaire; 9/22/2001:"In Escoffier's view, bisques fell into the "puree" family, a category in which a puree of the main ingredient formed the base, and rice, bread, or starchy vegetables the body."
Wisdom comes with age, but sometimes age comes alone.