These are turbulent times in Brazil
Land is a burning issue in Brazil.
Ecologists are reclaiming the Amazon; economists are plotting new ways to harness its farms.
And in this vast country, where the largest private estate is as big as Connecticut, the landless want property of their own.
At the heart of it all is the vexed issue of property rights - the right to own land, or even the right to own a shack in the urban slums.
Almost a year after the election of Workers' Party leader Lula, or Luiz Inacio Lula da Silva, having a former shoe shine boy as president has brought hopes of radical change.
Leading a quiet land reform revolution is Joao Pedro Stedile, a soft-spoken, bearded intellectual who has been credited with transforming Brazil's Landless People's Movement (MST) into the biggest non-party political pressure group in the world.
"The MST has two historical objectives," Mr Stedile told the BBC during a university student debate in Sao Paulo on "Democratising the Media".
"The first objective is to fight poverty in rural areas. We cannot accept living in such a rich country with so many poor people.
"The second objective is to fight against social inequality, for a fairer society."
Mr Stedile said that "Brazilian society is at a crossroads" and insisted that now was the time to chose an economic model for the country.
Mr Stedile questioned whether the president's commitment to eliminate the big estates and fight for land reform would be effective and insisted that Lula's government was a "transitional government, in permanent dispute".
Yet the rise of an organised landless people's movement with friends in high office worries those at the other end of the political spectrum.
Lula met MST leaders earlier this year
The MST's part in some high-profile invasions of private land is seen by opponents as a threat to investment.
"It's a political movement, with the intention of socialism in Brazil," said Renato Ticoulat, vice-president of the Sao Paulo Chamber of Commerce and a former president of the Rural Society, which represents landowners.
"This is really a problem for Brazil. The [land] owners haven't any security. And they don't have investment.
"Without investment, we have no employers, and the men don't have jobs."
A majority of Brazilians live in the slums of big cities, the so-called favelas, worlds away from the fierce debates over who should control farm land.
But here too property rights are becoming important.
Town planners want everyone to have a formal address, a proper name for every dirt road and a number for even the most precarious shack.
And in some of the slums, such as Rocinha which is the biggest in Brazil, there has been quite a lot of development, with sewers and a proper water supply having been installed.
Technically, it has been redesignated a neighbourhood instead of a slum.
But you only have to walk one or two streets away from the main road, and the infrastructure disappears.
Very slowly, slum dwellers are being given legal title to such properties as Brazil adopts ideas from the Peruvian economist Hernando De Soto.
"It's not that people don't have property and possessions in developing countries," Mr De Soto said.
"It's just that the rules have not been cast in such a way as to reflect the real needs and the social contracts among themselves."
Mr De Soto believes property rights are the key for bringing the dynamism and entrepreneurial capacity you find in the slums into the formal economy.
"It is the property that actually carries the value of capital around," he said.
"In most of the third world you have homes that on average can range from anywhere between $1,500 and $70,000."
By bringing these homes into the statistics, "you have an accumulation of assets on the basis which you can create capitalist system that also involves the poor."
Property rights are still a relatively abstract concept in the favelas.
The idea excites World Bank officials more than it does the people who live here.
But while gangs of children playing in the streets of Rocinha care more about football, Brazil's future is being decided by efforts to harness new and radical ideas about property.