In Fukuyama's words, human dignity is the hallmark of the X factor. This means that if person 1 believes that person 2 has human dignity, then Person 2 falls in Person X Factor 1. If you once again imagine the red line separating humans from nonhumans: the red line is human dignity. Anyone who I deem to lack human dignity has crossed the red line and is now no longer considered human. It is possible that Person 2 believes that Person 1 does not have human dignity even if Person 1 believes that Person 2 does. This is because the red line representing human dignity changes from person to person