White horses and orphan colts

On the recent discussion of radial categories (see replies to Oops, I did it again), what do the linguists/philosophers out there make of these statements attributed to Huizi (a leading member of the "School of Names"):

"A white horse is not a horse."
"An orphan colt has never had a mother."

Correction (28/6/01)

Oops, that wasn't Huizi, it was Gong-sun Long (the other main person in that particular school). Huizi (also known as Hui Shi) was the guy who said things like "The heavens are as low as the earth; mountains are on the same level as marshes."