Hitler was merely a figurehead. The origins of Hitlers policies came from the US and England. And yes, they were deemed to be scientific. Also let's not forget the other henchmen in his ranks Himmler, Goebbles, and Mengele.
Eugenics was definitely based on Science of the time. Now eugenics has been rebranded with the name Bioethics. It originally came out of Cold Springs Harbor where much of the current Human Genome research is taking place.
"Hitler and his henchmen victimized an entire continent and exterminated millions in his quest for a so-called Master Race.ť
But the concept of a white, blond-haired, blue-eyed master Nordic race didn't originate with Hitler. The idea was created in the United States, and cultivated in California, decades before Hitler came to power. California eugenicists played an important, although little known, role in the American eugenics movement's campaign for ethnic cleansing.
Eugenics was the racist pseudoscience determined to wipe away all human beings deemed unfit,ť preserving only those who conformed to a Nordic stereotype. Elements of the philosophy were enshrined as national policy by forced sterilization and segregation laws, as well as marriage restrictions, enacted in twenty-seven states. In 1909, California became the third state to adopt such laws. Ultimately, eugenics practitioners coercively sterilized some 60,000 Americans, barred the marriage of thousands, forcibly segregated thousands in colonies,ť and persecuted untold numbers in ways we are just learning. Before World War II, nearly half of coercive sterilizations were done in California, and even after the war, the state accounted for a third of all such surgeries."
"Hitler's concept of concentration camps as well as the practicality of genocide owed much, so he claimed, to his studies of English and United States history. He admired the camps for Boer prisoners in South Africa and for the Indians in the wild west; and often praised to his inner circle the efficiency of America's extermination - by starvation and uneven combat - of the red savages who could not be tamed by captivity." P. 202, "Adolph Hitler" by John Toland