Supreme Court Justice Clarence Thomas used a public address at the University of Texas at Austin to deliver one of his most direct critiques of progressive political philosophy to date, warning that the ideology poses an existential threat to the founding principles of the United States as the country approaches its 250th anniversary.

Speaking to a packed auditorium of law students, faculty and visitors, Thomas, the court’s longest-serving member, described a spirit of “cynicism, rejection, hostility and animus” that he said has taken hold across significant portions of American society, laying particular blame at the feet of universities and intellectuals for cultivating what he characterised as a rejection of the nation’s founding premises.

“Progressivism seeks to replace the basic premises of the Declaration of Independence and hence our form of government,” Thomas said. “It holds that our rights and our dignities come not from God, but from government. It requires of the people a subservience and weakness incompatible with a constitution premised on the transcendent origin of our rights.”

He urged the audience to stand up for their principles rather than retreat into pragmatism or institutional accommodation of ideas they believed to be wrong, suggesting that a generation of lawyers and public officials had failed the country by describing themselves as institutionalists or thoughtful moderates while failing to articulate the philosophical case for what the founders actually built.

Thomas also offered a more personal and lament-laden thread to the address when responding to a student question about judicial collegiality, noting that the generational change on the court since his early years has brought different norms around civility and cross-ideological friendship that he said may eventually “infect” the broader judiciary if not consciously resisted.

“When I said a lot of that, it was when I first went to the court. That was a different court. That was a court that was a World War II generation,” Thomas said, invoking the late Justice Sandra Day O’Connor as an example of someone who had worked actively to maintain cross-ideological relationships as a structural value rather than an incidental bonus of judicial life.

The address was part of a broader lecture series the University of Texas organised to mark the Declaration of Independence’s 250th anniversary, and the tone reflected what has been a notable shift in Thomas’s public posture over the past several years, from a justice who was conspicuously reticent about speaking publicly to one who has increasingly used law school forums and invited addresses to lay out a comprehensive constitutional philosophy.

His appearance drew both applause and protests on campus, reflecting the polarised reception that any high-profile conservative public figure now generates at a major research university, and his remarks were carried live on C-SPAN, giving them a wider audience than most judicial public appearances receive.