Wow. You, Mr. Lees, can most certainly scathe with the very best. Seriously, I enjoy very much your style (having read many of your articles).
Philosophy is where we ask 'why' in secular terms. It cannot be empirical. That does not make it illegitimate. It is not only legitimate, but inherent to being human. No scientist has sought to discover, as a scientist, what the ethic of justice must be.
Even though I have discovered that the ethic of justice must be an 'ought from is' (something no known philosopher has ever attempted), that has to do with a requirement of universality (in 'real justice', commonality)--which philosophers had recognized as a requirement for justice. I am far from the first person to recognize the place of mutual respect in justice. That justice is wholly contained within material existence (both its determiner and its referents) in real justice takes purely personal, inherently arbitrary beliefs (secular/ideological or sacral/theological) out of the matter.