The publication of Polish astronomer Nicolaus Copernicus’s De revolutionibus orbium caelestium (On the Revolutions of the Celestial Spheres) caused a stir among both scientific and religious communities in the mid 16th century. Postulating that the earth turned on its axis and with the other planets orbited the sun, Copernicus’s work challenged the long-held theories of Ptolemy that claimed the earth was the center of the universe. Likewise, De revolutionibus was condemned by the Church for challenging the centrality of man and the literalness of the Bible. Haverford’s copy includes underlinings and marginal annotations in two hands, including passages to be censured. This volume is part of the William Pyle Philips Collection of Rare Books, which contains many fine volumes representative of Western humanistic thought.