The document summarizes the philosophical views of several thinkers on human nature, including: - René Descartes viewed humans as both thinking and physical substances. - Karl Marx believed human nature is derived from labor and productivity. - Thomas Hobbes saw humans as motivated solely by desires and self-interest in a "state of nature." - Jean-Jacques Rousseau thought humans were born good but corrupted by society. - Jean-Paul Sartre and Karl Jaspers described ways to attain authentic human existence through freedom and responsibility.