Contrary to the these of Gibbon, Spengler and Toynbee, the author states ""If it is true that there is some kind of causation which inevitably brings about the fall of cultures or civilizations the history of the Roman Empire cannot be used to prove it."" He begins his study in the second century -- the Empire's successful period; discusses the changes in the third century about which, he says, Rome could do nothing; examines the crucial fourth century in which events became overwhelming for the Empire: the difficulty in controlling large landowners and the expanding bureaucracy, the increase of the division between the eastern and western Empire, the uncontrollable stream of the Germanic peoples from the north; and concludes in the sixth century, indicating along the way what changes took place and why. The failure of Rome to maintain central governmental authority, to regulate the succession to the throne, to handle finance, foreign affairs and the army became the failure of the West, but a failure, the author insists, which could have been avoided. His conclusion: ""there is no one great and portentous lesson to be learned from the history of the Roman Empire"". A book which is handled deftly, succinctly, in a non-technical manner -- a readable thesis.