What does "Implies each other" or "Implying each other" mean?
The context is from:
"My body and I are not, therefore, mutually exclusive; rather, each implies the other."
I believe the quotation is from Brendan Sweetman's book about the existentialist Gabriel Marcel.
It's a philosophical concept that the mind and the body of an individual are not truly separable: there can be no "I" if its body doesn't exist, and symmetrically, if there's a body, then it follows that there is some kind of "I".
The author is metaphorically using the language of formal logic. As it is a metaphor, the imagery is more important than the exact meaning. The meaning is that "If the body exists then I exist" and "If I exist then the body exists", and "the mind and body are not separate". The language suggests logical precision.