For Altair Jose Algayer, patrolling the Tanaru indigenous areaAn area of north-west Brazil covering around 4,000 hectares. was another day's work. But the FunaiA Brazilian government agency responsible for protecting indigenous people. agent found, on 22 August, on a hammock outside a straw hut, a body covered in macaw feathers. The person known as "the loneliest man in the world" was dead. 

Nobody knew his name. Anyone who had tried to contact him had been driven away with arrows.

Most of his tribe was murdered in the 1970s and 1980s by farmers and loggers who wanted to take their land. In 1995 six more were killed by illegal miners, leaving him as the only survivor.

He had lived on his own ever since, with outsiders banned - for his protection - from entering the tribe's territory. Funai members observed him from a distance, and once managed to film him cutting down a tree.

They also found over 50 huts he had built, each containing a 10 foot hole, and pits with sharpened stakes at the bottom for trapping wild animals. His other food seems to have been maize and manioc which he planted, honey and fruit such as bananas and papayas.

One expert, Marcelo dos Santos, believes that he had placed the macaw feathers on himself, knowing that he was terminally ill: "He was waiting for death. There were no signs of violence."

Since most humans live in communities, those who do not are a source of great fascination. Daniel DefoeAn English trader, writer, journalist, and spy. His novel Robinson Crusoe is considered one of the first English novels. 's 1719 novel Robinson Crusoe, about a man cast away on a desert island for 28 years, is one of the most widely translated books in history. 

Earlier this year Werner HerzogA German film director whose films include Fitzcarraldo. published The Twilight World, based on the true story of a Japanese soldier who lived in the jungle on an island in the Philippines for 29 years after World War Two ended. He believed that the war was still going on and his comrades would come back to rescue him¹.

Some people, though, embrace the solitary life through their own choice. Many have a strong religious faith, choosing to escape the distractions of daily life and focus on their relationship with God. 

This can take extreme forms. In the 5th Century, St Simeon Stylites chose to live on a small platform on top of a pillar in the Syrian desert. In medieval times, Julian of Norwich volunteered to be an anchoriteThe term derives from a Greek word meaning to retire or retreat., sealed in a bare cell attached to a church.    

Even today there are similar examples. Since 1993 a Georgian hermit called Maxime Qavtaradze has lived on top of the 130-foot Katashki Pillar in the CaucasusA mountainous region between the Caspian Sea and the Black Sea, including Georgia, Armenia, Azerbaijan and part of Russia.. 

The writer Sara Maitland, who has lived on her own for three decades, insists that solitude and loneliness are two different things: "Spending time alone is in fact spending time with the person you know best of all and who knows you better than anyone else does. Solitude deepens self-knowledge."

She believes that society should emphasise what Wordsworth called "the joy of solitude". Children should be sent to spend time alone in their rooms as a reward, not a punishment. 

Yes: Humans are social creatures, brought up to be part of a family or tribe. However much some of us like being alone, there are always moments when we feel the need for the company of other people.

No: We all need to spend time away from others so we can think our own thoughts without interruption. Some people are extremely independent by nature, and happily embrace a solitary life.   

Or... None of us are ever truly alone. Even if we are away from others, we carry thoughts and memories of the people who are important to us. And many religious people also feel the presence of deitiesGods or goddesses..