Israeli President Shimon Peres says science has changed global governance and can be neither conquered nor defended by armies.

His opening remarks to a roundtable discussion on education and innovation at Rideau Hall drew obvious parallels to Israel's current fears of Iranian nuclear development.

But Peres, in Canada for a five-day state visit, gave a nuanced address that avoided politics in favour of a more philosophical discussion.

The Nobel laureate said science cannot be controlled or arrested and it doesn't respect borders or laws.

"The major thing is the world is becoming ungovernable," he said. "The real force in our time is no longer politics, but science.

"And science took away the strengths of politics."

In comments that will echo on Parliament Hill where the Conservative government faces sharp criticism for ramming through an omnibus budget bill that rewrites dozens of statutes, Peres said citizens now must be persuaded rather than ordered.

"We shall have to act by consensus, by agreements; spend much more time to reach an agreement."

Gov.Gen. David Johnston opened the hour-long panel with academic and business leaders by lauding Israel's scientific prowess in turning desert into arable land, then building a "start-up" nation.

"In our discussion today, we think about our two nations becoming smarter together," said Johnston.

Peres was more provocative.

The 88-year-old statesman, twice prime minister of Israel, said wars need not be fought over land in the future and science can't be conquered by arms. But he cited academics who've said human aggression will still cause wars.

"Is it impossible to change human nature? Who told you so?

"The minute we shall overcome ourselves . . . you will have the combination of non-governmental management based on goodwill, answering individual tastes and trying to improve human self-control."

Self control is vital, he added.

"We need it because the alternative is very dangerous. Otherwise, crazy people with nuclear bombs in their hands can really create catastrophe."

Following the round table, Peres witnessed the signing of a memorandum of understanding between the Royal Society of Canada and the Israeli Academy of Sciences and Humanities. Brain science will be the first area of collaboration.

The Nobel laureate then took part in a commemorative tree-planting ceremony on the grounds of the Governor General's residence.

Peres appeared bemused by the size of the eastern white pine – a symbol of peace among the Iroquois – and asked its age. An arborist explained that the tree he was ostensibly planting, which stood about six metres tall, was 15 years old.

President more cautious on Iran

Peres has been a fixture in Israeli politics since 1959, serving in 12 cabinets. He is currently the country's head of state – a largely ceremonial role – but remains an influential figure and a perceived leavening voice to hawkish Prime Minister Benjamin Netanyahu.

The president's five-day trip to Canada began as Netanyahu first called for an early parliamentary elections, but then reversed his plans and announced a revamped coalition government, amid talk of an "existential threat" to Israel from Iran's nuclear program and the need for "much-needed stability" and "close co-operation on Iran."

Peres had private meetings with Prime Minister Stephen Harper and interim Liberal leader Bob Rae Monday, before a state dinner in his honour Monday evening at Rideau Hall.

Opposition Leader Tom Mulcair, who was attending events outside Ottawa on Monday, is scheduled to meet with Peres later on Tuesday before moving on to Toronto on Wednesday and visiting Montreal on Thursday.

Harper's Conservative government has drawn considerable criticism for dropping Canada's traditional, self-styled "honest broker" role that supported both Palestinian and Israeli ambitions in the region.

Peres has drawn no distinction in his public remarks about Canada's past and current positions.

This state visit by Peres follows Netanyahu's brief stop in Ottawa in March.

Netanyahu came looking for support for the idea of a pre-emptive strike on Iran's nuclear program. But Harper, despite echoing Netanyahu's concerns about Iran's intentions, expressed the desire for a peaceful solution.

Peres has repeatedly spoken of the need for an international, diplomatic solution and has openly questioned whether a pre-emptive strike would do anything more than delay Iran's acquisition of nuclear weapons by a couple of years.