Worldviews affect human behavior, and how we behave affects the world around us. Animism and so-called higher religions remain influential worldviews; but the scientific worldview is comparably significant, and has undergone drastic change during the twentieth century. The physical science ideal of mathematical precision and predictability, as elaborated by Galileo, Newton, and their heirs, underwent an amazing transformation in the twentieth century when Big Bang cosmology substituted an expanding, unstable universe for the Newtonian world machine. As a result, a grand convergence of the sciences seems to be emerging around an evolutionary vision of how new aspects of reality emerge locally from new levels of complexity, like the heavier atoms, forged in stellar furnaces, the living molecules that arose in earth's primordial seas, and the symbolic systems invented by human societies perhaps as recently as forty thousand years ago. History, once a hopelessly inexact laggard among the sciences, might even become something of a model for other disciplines, since it deals with the most complex levels of reality we are aware of, that is, the world of agreed-upon meanings that guides our interaction with one another and with the biological, chemical, and physical worlds around us.