Existentialism is a philosophical movement focused on individuality and making one's own reasoned decisions. The major thinkers were Soren Kierkegaard, Martin Heidegger, and Jean-Paul Sartre. Kierkegaard believed people must be responsible only to God's judgments in their choices. Heidegger built on this, believing authenticity is the only virtue. Sartre believed existence precedes essence, meaning people create their own essence through free will and choice alone.