UNSW academic Katharine Gelber has been recognised for her work on human rights, delivering the prestigious Mitchell Oration at the Adelaide Festival of Ideas.

Associate Professor Gelber, from the Faculty of Arts and Social Sciences, used the high-profile lecture to define freedom of speech and its limits.

Associate Professor Gelber was selected by the Equal Opportunity Commission of South Australia to deliver the Oration, which is held every two years. Others who have delivered the lecture include barrister Geoffrey Robertson and former United Nations High Commissioner for Human Rights Mary Robinson.

The Mitchell Oration recognises Dame Roma Mitchell's lifelong advocacy for human rights and preventing discrimination. Dame Roma served as the first female judge of the Supreme Court of South Australia and later became the Chair of the Australian Human Rights Commission. A strong advocate of the rights of women and and Indigenous and ethnic Australians, she was the first woman to be appointed Governor of South Australia.

"It's a great honour to deliver this prestigious lecture," said Associate Professor Gelber, who is based in the School of Social Sciences and International Studies. "It's topical to look at freedom of speech today, in the context of anti-terrorism legislation nationally."

In the lecture she was critical of the view that achieving equality is as simple as treating everyone the same way.

"[I am] critical of the view that equality must mean sameness ... real, substantive equality can only be achieved by recognising the concrete circumstances and contexts within which individuals find themselves over human rights," she told the audience.

Read the full speech.