Social science fiction is a subgenre of science fiction, usually soft science fiction, concerned less with technology/space opera and more with speculation about human society. In other words, it "absorbs and discusses anthropology", and speculates about human behavior and interactions. Exploration of fictional societies is a significant aspect of science fiction. It can often be precautionary as in Brave New World, or 1984, or Fahrenheit 451. It can criticize the contemporary world and present solutions, or can portray alternative societies. It can examine the implications of ethical principles.