I really like the article about human dignity. If it is “tenuous”, then this is because of more than its youth as a concept.
If human dignity and human rights equates with the formula “the maximum benefit and minimum harm available” to someone, then what is “available” can vary a lot.
The empathic response to pain – feeling pain because someone else is in pain – is easily disrupted. We have to approve of somebody before we can feel pain in response to their pain, and therefore want to help them (empathic concern and helping are all of a piece). We can disapprove of somebody for a number of reasons: because of their behaviour, or because they belong to a different group, especially a group that we feel threatens our own.
So the history of human dignity has been the history of the widening of the “circle of concern”: whom to include within our moral circle of concern.