Which named principle says Earth is not in a specially favored central position?

The named principle stating that Earth is not in a specially favored central position is the Copernican principle.

In its modern form, the principle says that humans and Earth are not privileged observers of the universe. It grew out of the intellectual shift associated with Nicolaus Copernicus, whose heliocentric model removed Earth from the center of the planetary system. The modern name was introduced by cosmologist Hermann Bondi in the mid-20th century.

The Copernican principle is related to, but not identical with, the cosmological principle. The cosmological principle extends the idea by assuming that the universe is broadly homogeneous and isotropic on sufficiently large scales. The Copernican principle concerns the lack of a special observer or location.

A common historical nuance is that Copernicus himself primarily sought a more orderly mathematical account of planetary motion. The broader philosophical idea that humanity occupies no privileged cosmic position developed more fully through later thinkers, including Giordano Bruno and modern cosmologists.