Calvin and Hobbes is a daily comic strip by American cartoonist Bill Watterson that was syndicated from November 18, 1985 to December 31, 1995. It follows the humorous antics of Calvin, a precocious, mischievous, and adventurous six-year-old boy, and Hobbes, his sardonic stuffed tiger. The pair is named after John Calvin, a 16th-century French Reformation theologian, and Thomas Hobbes, a 17th-century English political philosopher. At the height of its popularity, Calvin and Hobbes was featured in over 2,400 newspapers worldwide. As of January 2015, reruns of the strip still appear in more than 50 countries. Nearly 45 million copies of the 18 Calvin and Hobbes books have been sold. Calvin and Hobbes is set in the contemporary United States in an unspecified suburban area. The strip depicts Calvin's flights of fancy and his friendship with Hobbes. It also examines Calvin's relationships with family and classmates. Hobbes' dual nature is a defining motif for the strip: to Calvin, Hobbes is a live anthropomorphic tiger; all the other characters see him as an inanimate stuffed toy.