There are discussions in our tradition of sentient non-humans, as well as of additional worlds (or universes, which could be parallel universes). The question as to whether a non-human could convert has never been addressed since we have yet to meet a sentient non-human (outside of science fiction literature). Those goyim (the so-called “fundamentalists”) who hold that the “King James Version” of Taanach is the absolute and only truth and must be understood without reference to any external sources, get freaked out over the possibility of life on other worlds – but that shouldn’t be an issue for any of us since we hold by Torah she baal peh.
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