Reincarnation

 Sefer HaIkkarim (4:29) Cabalists argued—that the soul is not a material power but an independent substance and just as the spiritual substance entered the human body when it was created, it is possible that after having functioned in one human body, it may return and live in another. But this is not correct. The divine Wisdom did indeed decree that the spiritual substance, which by its nature is not a free agent, should dwell in the human body in order that it may become a free agent in the body, because this is no doubt a valuable quality in it. So much so that, as we are told by the Rabbis, the angels made a mistake and when God created man, they wanted to worship him … This was because he was a free agent and they were not. Nevertheless, why should a soul which has already functioned in a human body and has become a free agent, return to the body again? And why should the seminal drop have the capacity to receive a soul which has already functioned in a body rather than to receive a soul which has not functioned in a body and is not a free agent? A still less likely view is that of those who say that human souls are transmigrated into bodies of animals. God knows.