Definition from Wikipedia: Human sacrifice is the act of killing one or more human beings, usually as an offering to a deity, as part of a religious ritual.

The person to be scarified can be part of a ritual with or without consent, but it poses less moral problems if the person consent to the sacrifice.

For many societies before the classical age, the ritual of human sacrifice was a common practice. The custom ceased before the middle ages mostly because of religious reasons. But is it possible for a society to keep those practices acceptable during the middle ages and beyond (with or without the victim's consent)?