Last Updated: Wednesday, 2 August 2006, 06:42 GMT 07:42 UK
By Stephen Gibbs
BBC News, Cuba
On the streets of Havana there has been a remarkable sense of calm, almost nonchalance, in the face of the dramatic news that President Castro has undergone complicated surgery to stem intestinal bleeding.
People have been going to work as normal. Shops remain open. Cinemas are full.
In the shadow of one of the posters of the smiling president that last year were put up around the capital, pasted with the words "Vamos Bien" ("we are doing well"), Dinorah Padron, a retired nurse in her 60s, expresses an opinion that reflects the thoughts of many Cubans of her generation.
"We think he will be better very soon", she says. "He's healthy".
After 47 years in power many assume that President Castro will live, if not for ever, then at least for the foreseeable future.
"He has to recover", said David Santos, 54, who was wearing a revolutionary T-shirt and was on his way to see his grandchildren. "He is our leader, the maximum, the best."
Just a few Cubans are not hoping for a swift recovery.
In the shade of Havana's central park, a man who preferred not to give his name said he was rejoicing at the news.
"I think he is dead," said the man. "This is a totalitarian government. They never tell the truth."
In the statement read out on Cuban TV, Fidel Castro said that because of the special situation Cuba finds itself in - threatened, as he puts it, by "the empire" (the US) - the precise details of his health have to remain a state secret.
He wrote that he was "feeling fine", and in a "stable condition".
But owing to the severity of his health problems, all the power that one of the world's most charismatic leaders once held, is now in his hands of his brother.
Raul Castro is something of an enigma in Cuba.
Some say the 75-year-old Cuban defence minister is far more hard-line than his elder brother.
Others say he is the practical one, the great administrator behind the throne.
Five years ago, Fidel Castro himself offered his own analysis: "He is in good health," the president said.
"After me, he is the one with the most experience. People should note his attention to detail, his meticulousness, his honesty".
Since becoming Cuba's temporary president, Raul Castro has not appeared in public.
Perhaps he will in the coming days. But he faces a difficult task.
For most Cubans, there really is only one President Castro.