From the experts:
The ancient name Horace sounds fustily fuddy-duddy, and yet, with the resurrection of Homer, and the new interest in old Roman names...who knows. Its early popularity--it was in the Top 100 at the turn of the last century-- was spurred by admiration for the Roman poet Horace (born Quintas). Influential in American culture were newspaper editor Horace ("Go west, young man") Greeley and educator Horace Mann; Horace Silver is a jazz legend. There's also a Harry Potter character named Horace Slughorn.