Unity covers a wide range of loosely connected ideas in science, differently analyzed by different interpreters. Generally, they are expressions, or echoes, of the idea that science can succeed in providing one consistent, integrated, simple, and comprehensive description of the world. This entry will provide a historical perspective on such ways of thinking about unity in science. (Readers should bear in mind that the real history is much more complex and interesting than the following microsketch, which is intended only to introduce the leading ideas.)

Mechanisms and Laws

The scientific revolution of the seventeenth century involved consolidation of the "mechanical (or corpuscularian) philosophy" according to which natural phenomena are to be understood in terms of shaped matter in motion, with the natural world likened to a giant mechanism. Natural philosophy could look for unity in this regard by thinking of...