The phrase "an optimistic belief" is correct and usable in written English.
You can use it when discussing a positive or hopeful perspective on a situation or outcome.
Example: "Her optimistic belief in the project's success motivated the entire team to work harder."
Alternatives: "a hopeful conviction" or "a positive outlook".
This picture identifies the communal hedonism of swimming with an optimistic belief in social progress.
While some of his tales exhibit an optimistic belief in the ultimate triumph of goodness and beauty (e.g., "The Snow Queen"), others are deeply pessimistic and end unhappily.
His pessimistic worldview, cemented by a Depression-era childhood, was tempered by an optimistic belief in extraterrestrial life that was rooted in the same lousy childhood.
In England, Queen Victoria ascended the throne and opened the age of industrialization, scientific advance and an optimistic belief in human progress to which she gave her name.
It engages with the key themes of modernism: the relativity of time, the impact of psychoanalysis, the power of myth, and an extended dispute between an optimistic belief in progress and a pessimistic vision of human nature.
Like a British village comedy of a certain style and vintage, "Where Do We Go Now?" is plucky, whimsical, mildly naughty and blithely sentimental, giving tragedy its due while holding to an optimistic belief in the goodness and fallibility of ordinary people.
Which is why I believe this Pew report is a call for an entirely different narrative, a commitment to the future of the human family, and it serves as a call for a political candidate with a more optimistic belief in the future of the human race.
As seen in the present study, the controls i.e. patients without GI-problems tended to have a more positive approach and a more optimistic belief in the future.
The catastrophic decision to let Lehman Brothers go bust, Blinder argues, was taken in large part because Paulson and Bernanke believed that the markets had used the six months since Bear Stearns was rescued to prepare for Lehman's failure — though how they came to hold such a naïvely optimistic belief is anyone's guess.
SACRAMENTO — A week after warning the Treasury Department that California might need an emergency loan of up to $7 billion, Gov. Arnold Schwarzenegger on Thursday sent another, more upbeat note expressing a "cautiously optimistic" belief that the state could find the money it needed in the credit markets.
Wojcicki has a (very) optimistic belief that if consumers knew how vulnerable they are to obesity and other preventable diseases, they could be significantly reduced.
