"A bitter struggle took place in the fourth century to maintain that the Son and the Holy Spirit were of the same substance as the Father and equally co-eternal and con-substantial. What the Church might take for granted today involved a century of struggle involving councils, creeds, emperors and church leaders. If you wish to understand both the issues at stake and the cross currents of this controversy, you could not do better than start with this faithful and vivid account of its theology and history, deftly woven together."