One example of a quote that inspires positive thinking is "Write it on your heart that every day is the best day in the year," by Ralph Waldo Emerson. Another example is "The greatest discovery of all time is that a person can change his future by merely changing his attitude," by Oprah Winfrey.
Emerson was an American poet and philosopher during the 19th century. He helped lead the Transcendentalist Movement, and one of his most famous poems is "Good-Bye." He also wrote well-known essays such as "Self Reliance" and "The American Scholar."
The quote by Oprah Winfrey implies that the quality of a person's experiences and her future are both dependent upon her thoughts and views about the world and herself. Oprah is a famous American talk show host, actress and philanthropist.
Another quote that inspires positive thinking is "Optimism is the most important human trait, because it allows us to evolve our ideas, to improve our situation, and to hope for a better tomorrow," by Seth Godin. Seth is an American author and public speaker. He founded Yoyodyne in 1995, which is an online company that uses games, scavenger hunts and contests to market different companies to users.