Whig history (or Whig historiography) is an approach to historiography that presents the past as an inevitable progression towards ever greater liberty and enlightenment, culminating in modern forms of liberal democracy and constitutional monarchy. In general, Whig historians emphasize the rise of constitutional government, personal freedoms, and scientific progress. The term is often applied generally (and pejoratively) to histories that present the past as the inexorable march of progress towards enlightenment. The term is also used extensively in the history of science to mean historiography that focuses on the successful chain of theories and experiments that led to present-day science, while ignoring failed theories and dead ends. It is claimed that Whig history has many similarities with the Marxist–Leninist theory of history, which presupposes that humanity is moving through historical stages to the classless, egalitarian society to which communism aspires.