Catholica is organized into three sections--"Tenet," "Locus," and "Spiritus"--each with three themed subdivisions. Part one introduces the centerpieces of the faith, surveying symbolism in the artistic representation of the holy family, apostles, and saints in stories from scripture. The second part examines places of worship, identifying the essential elements of the cathedral and presenting evocative images of roadside shrines. The third part explores celebrations and traditions, in addition to personal devotional tools and jewelry.
For each of the nine central themes of the faith, introductory text is followed by pages that look in-depth at paintings and artifacts, identifying and explaining the symbolism and stories depicted. As the book progresses, readers build up their knowledge of the entire Catholic visual code--the symbols that define Catholic practice, the attributes of the saints, the parts of the cathedral--allowing them to interpret all Catholic imagery and objects wherever they find them and consequently to better understand the tenets, sites, and rituals of this faith.