I’m sure the point has been made before, but it occurs to me that to describe shameful episodes like racial eugenics as “pseudoscience” risks the “No True Scotsman” fallacy.

This is an early (possibly the first) telling of the No True Scotsman story, by Anthony Flew:

Imagine Hamish McDonald, a Scotsman, sitting down with his Glasgow Morning Herald and seeing an article about how the “Brighton Sex Maniac Strikes Again”. Hamish is shocked and declares that “No Scotsman would do such a thing.” The next day he sits down to read his Glasgow Morning Herald again; and, this time, finds an article about an Aberdeen man whose brutal actions make the Brighton sex maniac seem almost gentlemanly. This fact shows that Hamish was wrong in his opinion, but is he going to admit this? Not likely. This time he says: “No true Scotsman would do such a thing.”

It would similarly be fallacious to say, “No scientist would claim to assemble evidence for white supremacy. Ah, I see that a whole raft of highly distinguished scientists argued for white supremacy, and a few still do. Well, they are not true scientists.”

If “Racism is pseudoscience” is just a way of saying “racism is false,” then I agree with it. But if it’s meant to imply that the actual practice of science–science as a real human activity–would never support racism, then it’s false. Science did support racism, and that tendency lingers in some quarters. Racist scientists are truly scientists in the sense that they practice that occupation and participate in that social institution. They’re wrong, but that shows that science is susceptible to error–both empirical and moral. It’s not helpful to try to evade the problem by definitional fiat.

See also: is science republican (with a little r)? and is all truth scientific truth?