We are an individual human being in the body first at conception and remain an individual human being in the body until death, artificially or naturally arrived at, along the continuum that is an individual human lifetime in the body begun at conception.
Slavery is unacceptable in an advanced civilization ... or is it? If it's enslavement for only a short time period, then harvest and kill the enslaved, is that okay?... They're only a few hundred cells.