It is a wrong conception when theosophists believe that reincarnation had no beginning and will have no ending. Reincarnation started in the Lemurian Age and will cease again at the beginning of the sixth Root Race or Age (about 7893 after Chr.). It is only a certain period of time in earth evolution during which mankind reincarnates. It was preceded by a most spiritual condition which precluded any necessity for reincarnation and there will follow again a spiritual state which will likewise obviate the necessity for reincarnation.
Source: Rudolf Steiner – GA 93 – The Temple Legend – Lecture 1 – Berlin, 23rd May 1904