If the traditional opinion were correct which ascribes the Tso-chuan to Tso Ch'iu-ming, a contemporary of Confucius, his work would be of the utmost importance as a source of historical information, though even in that case we might well doubt whether all the incidents which it relates are genuinely historical and might wonder how many of the speeches in which it abounds were the composition of Tso Ch'iu-ming himself. If, on the other hand, those scholars are right who assign it to the Han dynasty, while of less importance as a record of fact, the Tso-chuan is still one of the most valuable of the works which have come down to us from Chinese antiquity, part of its significance on that supposition being that it illustrates what were believed at the time of its composition early in the Christian era to have been the ethical ideals which were acknowledged in the period to which Confucius himself belonged.