Such important issues of the modern thought as freedom, will, and action have their roots not only in classical philosophy, but also in early Christian theology. The book aims to fill a gap in our knowledge about the theological roots of the issues mentioned. The author explores Christological contests of the 7th century on the issues of will and actions (energy) in Christ. The main source for the research are the acts of the western and eastern Church councils and writings of the most prominent theologians of the time. The author also thoroughly examines the preceding theological traditions associated with the names of Apollinarius of Laodicea, Theodore of Mopsuestia, Cyril of Alexandria and Severus of Antioch.