The environmental humanities comprise a large, growing, and diverse body of inquiry spanning a multitude of academic disciplines. Along with the social sciences, these humanities disciplines have long been devoted to the study of human affairs, leaving the natural sciences to study things such as ecology, ice sheets, and climate. Broadly, where humanities disciplines differ from social science ones is as follows: unlike, say, economics, which treats social phenomena as possessing universal qualities regardless of location, the humanities focus on the many ways different people make the world meaningful in various registers (e.g., through their ethical beliefs). The humanities thus acknowledge the relativity of belief, the intersubjective nature of human existence, the situatedness of life, the complex ways people apprehend the world, and the many disagreements that arise about moral, aesthetic, and existential issues. They pivot on the human capacity for free will, creativity, and imagination. They explore profound questions such as "How should we live?" "What are human rights?" and "What is justice?" For some humanist scholars, their aim is to identify "the best of human thought," using cross-cultural analysis, critical thinking, and engagement with the (often contentious) value questions avoided by many social scientists. Beginning in the 1960s and achieving considerable momentum since the start of the twenty-first century, a number of The International Encyclopedia of Geography.