Jonathan David Haidt is an American social psychologist and author.

French aristocrat and political thinker Alexis Charles Henri de Tocqueville transformed how the world understood democracy through his keen observations of 19th-century America.

Friedrich Wilhelm Nietzsche was a German philosopher and writer who started his career as a classical philologist and turned to philosophy early in his academic career.

Massimo Pigliucci is a professor at The City College of New York who has published 194 technical papers in science and philosophy and is the author or editor of 23 books. He is best known for the bestselling How to Be a Stoic: Using Ancient Philosophy to Live a Modern Life (Basic Books). He holds a PhD in evolutionary biology and has also worked as a producer, director, and writer.

Aldous Leonard Huxley was an English writer and philosopher.

The 14th Dalai Lama was recognized at age two as the reincarnation of the 13th Dalai Lama. Following the 1959 Tibetan uprising, he escaped into exile in India, where he lives as a refugee. He has authored works including two autobiographies — My Land and My People (1962) and Freedom in Exile (1991) — as well as The Art of Happiness, a landmark book in the field of positive psychology.