The novel plays with fiction and reality in telling a story about a Greek sage known as Copta, who features in a manuscript discovered by an Englishman centuries later.
"Distinguishing fiction is really hard not just for writers, but for anyone. We live under a barrage of information that we believe is real, even when it can't be," Coelho said in an interview in Geneva, released by his publisher Sextante.
This story "is based on values, and values are never fiction. They pass through time," the writer added.
The titular manuscript is a 1307 retelling of a meeting between Copta and the people of Jerusalem, just before Crusaders arrived in the late 11th century.
Copta "urges men and women in the city to seek wisdom in everyday life," the publishing house wrote in a statement marking the release of the new novel, which will have a first run of 100,000 copies.
Wednesday is also the 25th anniversary of the release of one of Coelho's most famous works, "The Pilgrimage," which tells of his experience along the Way of St. James, in Spain.
The award-winning author, who has held a seat at the Brazilian Academy of Letters since 2002, also has 13.5 million fans of his Twitter and Facebook pages.
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