Weltanschauung n. German; literally "world view," or a personal philosophy of life, one's view of the role of humans in the universe.
Related nouns include Weltpolitik, "world politics" (policy towards the world, or foreign policy), and Weltschmerz, 'world sorrow," (sadness at the world's woes, or pessimism).
From Sigmund Freud's Civilization & Die Weltanschauung (1918):
By Weltanschauung, then, I mean an intellectual construction which gives a unified solution of all the problems of our existence in virtue of a comprehensive hypothesis, a construction, therefore, in which no question is left open and in which everything in which we are interested finds a place. It is easy to see that the possession of such a Weltanschauung is one of the ideal wishes of mankind. When one believes in such a thing, one feels secure in life, one knows what one ought to strive after, and how one ought to organize one's emotions and interests to the best purpose.