Born into an immigrant family of successful bakers, Isaac Hecker was motivated by the dual desires to cultivate personal, mystical experience and to ameliorate social problems. The attempt to synthesize these somewhat disparate longings took him on a journey through eclectic political and religious movements. He participated briefly in the experimental utopian communities of Brook Farm and Fruitlands, where he examined Transcendentalism before his conversion to Roman Catholicism. He quickly joined the priesthood, first as a member of the Belgian order of Redemptorists and then as the founder of the Paulist Priests, a group that has become a leader in Catholic publication in America.

On 18 December 1819, Isaac Thomas Hecker was born to John and Caroline (Freund) Hecker, who had wed in 1811. Natives of Prussia, the Heckers had arrived in New York City before the turn of the century and had four other children by the time of Isaac's...