It's a reality Jesuit priest Father Frank Brennan is acutely aware of – it's the topic of his latest book, No Small Change.

"There is no Australian under the age of 56 who has voted in a successful referendum and there is no Australian under 69 years of age who voted in the successful 1967 referendum on Aboriginal rights," he says.

"It was a very modest change to the constitution, but it was carried overwhelmingly by the Australian people and it was that, that created the political momentum for change."

The issue will rears its head again on Monday, July 6 when Prime Minister Tony Abbott chairs a bipartisan summit with indigenous leaders.

While Father Brennan says he has "no idea" what the outcome will be, the Australian Catholic University law professor has a clear idea of what he would like to happen.

In No Small Change, he argues against grand plans to establish an Indigenous body and insert a racial discrimination clause at the same time as the referendum.

Instead he suggests a "modest change" is better than none and could be the best way to convince Australians to vote yes and get the ball rolling for more dramatic reform.

Father Brennan effortlessly recounts indigenous politics and policy post 1967, at Yarralumla's humble Jesuit House, partly because he, or his family, were involved in some of the most significant moments.

His father Sir Gerard Brennan was the 10th chief justice of the High Court and wrote the lead judgment on Mabo.

But after 30 years, he is well aware of the sensitivities as a "white fellow" in the public square concerned with indigenous issues.

"The role of someone like myself who is not indigenous, but is fully sympathetic to Indigenous aspirations is to try and administer the reality therapy of what's actually achievable and what are the realistic options," he said.

Most recently he has come under fire from Indigenous academic Marcia Langton who labelled his three-point plan towards constitutional recognition "dismissive and disrespectful of decades of Indigenous advocacy".

"You've always got to be very attentive to the place of indigenous leaders in staking their claims," he said.

"But it's always seemed to me, particularly with issues of constitutional change, that indigenous Australians can't do it on their own.

"To have a few of us there shaping the appropriate contours of the debate is a useful thing."

For his own part Father Brennan shapes the debate into three boxes that must be ticked to achieve the historic change: indigenous aspiration, workability in the existing constitution and public popularity.

And to tick all these boxes Father Brennan hopes indigenous Australians agree to defer "high ideals" for an Aboriginal advisory body and ban on racial discrimination, suggested by the expert panel's "dog's breakfast" 2012 report, and agree to a "symbolic compromise".

While the proposal for a non-discrimination clause is "attractive", Father Brennan said it would need significant "legislative cleaning up" to the Native Title Act, only possible if the Business Council of Australia, the National Farmers Federation and the Minerals Council could be convinced.

The advisory council is another sticking point.

Although he is a "strong supporter" he says Australians would be suspicious of a hidden agenda if an untested body was inserted into the constitution.

Instead Father Brennan hopes indigenous leaders agree to a small change with a guarantee from government that a statutory advisory body would be set up and later written into the constitution – if it worked, which history had shown could be problematic.

"If you have a group of Aboriginal leaders who have that task, largely based in Canberra, the risk is they will lose touch with the local Aboriginal communities who will then say they've lost legitimacy," he said.

He said the chequered history of past Aboriginal bodies such as the National Aboriginal Consultative Committee in the 1970s, the National Aboriginal Conference in the 1980s, and the Aboriginal and Torres Strait Islander Commission in the 1990s which all "ultimately fell over" showed the difficulty in Indigenous politics for the national voice to keep contact with remote communities.

Father Brennan counts former Prime Minister Kevin Rudd as a friend and was labelled a "meddling priest" by another former Prime Minister Paul Keating, so he freely acknowledges his political influence, but argues the "hard work" lies with changing the thinking of bureaucrats not parliament.

His interest in indigenous rights began when he was a University of Queensland law student in the 1970s at the height of land rights campaigning when "colourful" premier Joh Bjelke-Petersen was in power.

But when he later began his career in the priesthood he initially wasn't interested in working with indigenous people, instead it was the Jesuits' provincial who encouraged him to put his legal training to good use.

During the Wik debate, Father Brennan played the "useful service" of being an intermediary between angry farmers and Indigenous leaders.

It's a role he has continued always informed by the catholic tradition for justice for the poor, disadvantaged and marginalised.

After Jesuit postings in Kings Cross and northern Sydney, he's been based in Canberra for the past seven years and remains an adjunct professor at the Australian National University's College of Law and National Centre for Indigenous Studies.

But it was away from the hotbed of politics during last year spent in Boston that he wrote the book partly, he says, to be transparent and put his argument on the public record.

"One thing is not negotiable, there's no point in going ahead with anything unless you've got the overwhelmingly majority of indigenous Australians saying 'this is the way we want to proceed'," he said.

"That's what we're waiting for when Prime Minister Abbott meets with the Aborigines on July 6."

Father Frank Brennan will speak at a free meet the author event at the ANU on July 16 from 6pm. More information at www.anu.edu.au/events.