Nancy MacLean, a professor of history at the prestigious Duke University, baselessly argued in a recent lecture that a significant amount of libertarian thinkers were on the “autism spectrum.”

MacLean, the author of the controversial book Democracy in Chains, argued in a lecture last week at New York City’s Unitarian Church of All Souls that libertarianism is void of empathy because influential architects of the ideology were “on the autism spectrum.”

MacLean’s book, Democracy in Chains, a biography of economist James Buchanan, invited a wave of controversy following its publication. Even the progressive Vox.com published a scathing review of MacLean’s book under the title “Even the intellectual left is drawn to conspiracy theories about the right. Resist them.” The review called MacLean’s book a “conspiracy theory in the guise of intellectual history.”

Last week, during her event in New York City, MacLean fielded a question from a member in the audience about Buchanan’s alleged disdain for the poor. “Where do [Buchanan’s] motivations lie? Are they ones of personal greed? It seems like it’s a little grander, is it malevolence?”

In response, MacLean argued that the architects of libertarianism found difficulty in empathizing with others because a significant number of them were “on the autism spectrum.”

It’s striking to me how many of the architects of this cause seem to be on the autism spectrum. People who don’t feel solidarity or empathy with others, and who have kind of difficult human relationships sometimes. In Buchanan’s family, his grandfather had actually been a populist governor of Tennessee… he ended up a very bitter man but he was very well known, and Buchanan’s own parents wanted him to go into politics and have a political career. Buchanan says in his memoir, “there were early misgivings about my personality.” Like they knew he would never make it in politics. But who knows, this is speculation right? Part of me, since you’ve asked me in the way you have, part of me feels like there was this some kind of wound in him that he couldn’t be this political figure, and then he made it his mission to kind of debunk the whole of politics to show that no one who was in it was good. But I don’t know.

Shortly after, MacLean clarified her diagnosis as “speculation.” Later in the speech, another audience member referred to “autistic libertarians” while he posed a question to MacLean.

Troy Earl Camplin, a blogger who writes about living with Asperger’s syndrome and raising an autistic son, condemned MacLean in a post, accusing her of using “autistic” as a slur.

“I’ve discussed how ableist people like MacLean use autism as a slur, but I don’t think we’ve ever been accused of being the source of malevolent ideologies before,” Camplin wrote.

Camplin went on to explain that those on the autism spectrum are certainly capable of empathy.

“James Buchanan was a classical liberal. That is, he believed in small government, free markets, and that people should be generally left alone,” Camplin continued. “MacLean interprets this as being evidence of Buchanan being autistic (she doesn’t directly say it, but certainly implies it–which is her M.O. in her book, by the way). She accuses us of not feeling solidarity with other people and of not feeling empathy. Naturally, those of us on the spectrum know that we are certainly empathetic, as I myself have discussed several times–in some cases and ways, more so than others.”