Yes, but how to find that man? And how does he find his sucessor?
The five "Good Emperors" as Gibbons called them might have found a solution for that by adopting the ablest man as their sons and succesor. Nerva adopted Trajan who chose Hadrian who adopted Antonius Pius who selected Marcus Aurelius. But even this period of very good monarchic goverment (96-180 AD) came to an end when Marcus Aurelius let his son Commodus, who was unfit to rule, take the throne.
