The 17th-century French philosopher René Descartes famously said, “I think, therefore I am.” What Descartes meant by that was that he knew he existed because he was conscious of himself, which is what is called self-consciousness. Self-consciousness is a uniquely human attribute that all non-impaired individuals share. However, consciousness and self-consciousness are very different things, and the distinction is critical. For some reason, humans are uniquely endowed with consciousness and self-consciousness.