
Existentialism is a philosophical movement and social theory that originated in the 19th and 20th centuries. Existentialism is the belief that philosophical thinking begins with the human subject - not merely with the thinking subject, but the acting, feeling, living individual. Its starting point was that philosophical thinking must be the individual and his/her experiences, saying that moral and scientific thinking cannot suffice to understand human existence. The concept of living "authentic" (passionate and sincere) lives, necessary to understanding human existence, was coined by Soren Kierkegaard. The true essence of the individual was said to be his/her individuality as an existing being. Through one's own consciousness, Jean-Paul Sartre argued, humans create values and determine a meaning to their lives.