What is needed is a diagnostic tool that measures pain accurately. How can anyone judge their own pain levels reliably when they occupy a universe with nothing else In it ? And how can anyone have empathy for another's pain when it is not inside them? I would have thought the brain would have areas that light up during the experience or be pumping out some chemical that could be measured in the blood.
If we had this tool it would save the guilt ,stigma, suspicion and dodgy benefit assessments that we have to go through.