Leibnizian optimist is a term typically used to describe someone who believes that this is the best possible world that we could be living in. However, there are several other synonyms for this term, including Panglossian, Voltairean optimist, and utopian. A Panglossian person has a similarly positive outlook on life, believing that everything happens for the best and embracing even the toughest of challenges. Voltairean optimists tend to be more skeptical, but still hold onto the belief that human beings are capable of making the world a better place. Finally, a utopian is someone who possesses an idealistic vision for a perfect world where everything is just right. All of these words can be used interchangeably with Leibnizian optimist, each conveying slightly different shades of positivity or optimism.