Here are a few quotes by Martin Seligman, considered by many to be the “father” of Positive Psychology.
“I believe it is within our capacity that by the year 2051 that 51 percent of the human population will be flourishing. hat is my charge.”
“Habits of thinking need not be forever. One of the most significant findings in psychology in the last twenty years is that individuals can choose the way they think.”
“I’m trying to broaden the scope of positive psychology well beyond the smiley face. 
Happiness is just one-fifth of what human beings choose to do.”
“You can have meaning, accomplishment, engagement and good relationships, even if you are dull on the positive affect side.
“If we just wanted positive emotions, our species would have died out a long time ago.”
“Psychology is much bigger than just medicine, or fixing unhealthy things. It’s about education, work, marriage it’s even about sports. What I want to do is see psychologists working to help people build strengths in all thee domains.”
“On the relationship side, if you teach people to respond actively and constructively when someone they care about has a victory, it increases love and friendship and decreases the probability of depression.”
“Reaching beyond where you are is really important.”