Good answers so far, and as you can see the general consensus is fairly positive. Just to play devil's advocate, I'll say no. Splitting the empire territorially was solving the wrong part of a much more complicated problem. read more
The Splitting of the Roman Empire very likely enabled the Eastern Empire to exist far longer than it might have with Rome at its' center. The vast wealth of the Roman Empire was in the east, so Constantine moved the capital closer to maintain power over it. read more
Another correspondent cites Gibbon’s hypothesis, that Christianity was the leading cause of the fall of the Roman Empire. Gibbon’s idea is a crock. The Empire in the west was spiraling down for economic reasons. read more
In 393, two years before his death, Emperor Flavius Theodosius (Theodosius I), divided the Roman Empire into two parts. The Western Roman Empire Theodosius placed in the hands of his younger son Flavius Honorius, who he declared Augustus in 393 when Honorius was only nine years old. read more