Combining disparate elements of pernicious ideologies including eugenics, antisemitism, racial purity, and the German ideal of lebensraum ("room for living"), what eventually became Nazism informed Hitler's ethos as he rose to power.  His malignant weltanschauung eventually coalesced into the Final Solution.

Hitler's infernal vision metastasized quickly to infect the belief systems of top-tier Nazis.  Among other atrocities, Mengele used injections to attempt to change the eye color of his "patients" to blue to render them more Aryan.  When these experiments went sideways, the fiendish M.D. demonstrated a penchant for "tidying up."  One person testified to having witnessed the diabolical doctor kill fourteen sets of twins in one night with chloroform injections to the heart in order to make comparative post-mortem observations.

After the Allies won the war, the Nuremberg Trials were convened to assess the astonishing breadth of the human tragedy as authored by Hitler and his henchmen and mete out punishment for their actions.  The cruelty and depravity of Mengele and others, including Adolf Eichmann, shocked the world, were almost beyond reckoning, and subsequently inspired the establishment of the Nuremberg Code — which was tacitly endorsed by nearly every nation on earth.

The ten points of the Nuremberg Code for human experimentation are as follows: