Hard science is science that uses mathematics and experiments to get knowledge. In hard science, experiments have to be reproducible (if the experiment is done a second time, it will have to produce the same results as the first time). Hard science subjects include the natural sciences, which are about the natural world. These include physics, chemistry, biology, geology, astronomy, and botany. Soft science is any of the social sciences, including history, and political science. Psychology and sociology were once considered soft science but are now called hard sciences.
- Helmenstine, Ph.D., Anne Marie (February 18, 2012). "Difference Between Hard Science and Soft Science". http://chemistry.about.com/b/2012/02/18/difference-between-hard-science-and-soft-science.htm. Retrieved 2013-01-31.