New Delhi: Historian Romila Thapar on Saturday alleged that Jawaharlal Nehru University was being "slowly dismantled" and asserted that critical thinking if trampled upon would destroy the idea of a varsity.

She also said history was facing a threat of "infusion of imaginary theories" that were being used to "ground valid knowledge".

Thapar, 86, one of the first academics to join JNU when it was founded, said the varsity's first vice-chancellor, Gopalaswami Parthasarathi, along with many others, had helped build the institution with "meticulous" care.

"This is... very often ranked as equal to the better universities in the world. It is now, perhaps not surprisingly, being slowly dismantled," Thapar said at the launch of a book, titled GP 1912-1995, based on the life of Parthasarathi, a journalist, diplomat and academic.

Former foreign secretary Muchkund Dubey and former external affairs minister K. Natwar Singh were also present at the event.

Thapar's comments came in the backdrop of allegations by a section of academics that varsities, including JNU, were being targeted and the space for critical thinking and dissent was shrinking.

Thapar said that a university was a place not to just hand out degrees but to advance knowledge by raising doubts and questioning subjects critically. "Those in polity have to recognise these rights and nurture them. If they trample on them, they will destroy not only that particular institution but the very idea and the function of a university," she said.

Earlier, the octogenarian had, along with other noted academics, raised concerns over "rising intolerance" in the country after Kannada writer M.M. Kalburgi was shot dead in 2015.

Thapar said disallowing the freedom to debate and allowing only authorised ideas was an indication that those in power were "somewhat insecure".