I bought this book along with Creed, Councils and Controversies to complement Henry Chadwick's Vol 1 of Penguin History of the Church. The combination of these three books has given me a great grounding in early Church history. Doctrine and Practice in the Early Church selects from a broad range of sources from across all the doctrinal divides that appeared before Nicaea. From each theologian it then takes the few exerpts which best summarise their viewpoint - clearly a nightmarish editorial task! Very helpfully, the exerpts are in broadly chronological order (although within a broadly chronological structure sources are also grouped by theme).