Books about voyages and new discoveries were very popular in the first quater of the 18th century, there were written many stories of this kind but while Defoe was busy with politics he didn't think of also trying his hand at it. However one story in Steel magazine attracted his attention.
It was about a Scottish sailor, who lived alone 4 years and 4 months on a desert island. However, Defoe's hero, Robinson Crusoe, spend 26 years on a desert island. The novel was a praise of human labour and the triumph the men over nature. Labour and fortitude helped Robinson to endure hardships. They saved him from dispair. The very process of hard work gave him satisfaction. Robinson's most characteristic trait is his optimism.