Sentence:  Another traditional answer to the question of what makes us so different, popular for millennia, has been that humans have a non-physical soul, one that inhabits the body but is distinct from it, an ethereal ghostly <WSD>wisp</WSD> that floats free at death to enjoy an after-life which may include reunion with other souls, or perhaps a new body to inhabit. 
Meaning of the word marked with <WSD> tags:  An immeasurable, indefinable essence of life; soul.