As their civilisation grew, they needed to do more and more sophisticated mathematics to help them build and trade.
As well as warning about the relatively short-term loss of GPS, global communications and other satellite services, there is growing concern that a major solar storm could change civilisation as we know it.
More importantly it confirmed him in his sympathy and respect for the culture of the indigenous peoples of South America and also in his growing scepticism towards the philosophical and artistic achievements of the literate civilisations of the Old World.
Civilisations have grown by understanding and appreciating other perspectives.Kanwal Jit SinghCorruption in AfricaSIR - Your article ("Africa's unending war on corruption", Economist.com, February 3rd) is another sad reminder of our continuing failure in dealing with this chronic social malady.
The second is that the planetary-boundaries group derives most of its limits by looking at conditions during the Holocene the epoch since the end of the most recent ice age, in which human civilisations have grown up.
A new generation of budding discophiles, with peach fuzz where their ironic facial hair is still growing, suddenly discovered what their forebears long took for granted: Giorgio Moroder saved civilisation.
But when people see the growing effect of Osborne's cuts, they may remember that tax is the price we pay for civilisation.
In this he has the support of non-Malays, who worry about the growing assertiveness of Malay Muslims, and some of whom resented a recent ruling to make the study of "Islamic civilisation" compulsory in universities.
He was too sensitive to the thinness of the crust of civilisation to share the classic liberal faith in the market, but too clear-sighted to embrace the growing fashion for big-government solutions.
But the authorities in Canberra have responded to the growing number of asylum-seekers by building centres to isolate them in remote places, hoping that the vast, inhospitable distances between these prisons and civilisation will deter others from coming.
