An ideology is a set of beliefs or philosophies attributed to a person or group of persons, especially those held for reasons that are not purely epistemic, in which "practical elements are as prominent as theoretical ones." Formerly applied primarily to economic, political, or religious theories and policies, in a tradition going back to Karl Marx and Friedrich Engels, more recent use treats the term as mainly condemnatory.
The term was coined by Antoine Destutt de Tracy, a French Enlightenment aristocrat and philosopher, who conceived it in 1796 as the "science of ideas" to develop a rational system of ideas to oppose the irrational impulses of the mob. In political science, the term is used in a descriptive sense to refer to political belief systems.
The term ideology originates from French idéologie, itself deriving from combining idéā (ἰδέα; close to the Lockean sense of idea) and -logíā (-λογῐ́ᾱ).
The term ideology, and the system of ideas associated with it, was coined in 1796 by Antoine Destutt de Tracy while in prison pending trial during the Reign of Terror, where he read the works of Locke and Condillac. Hoping to form a secure foundation for the moral and political sciences, Tracy devised the term for a "science of ideas," basing such upon two things:
the sensations that people experience as they interact with the material world; and
the ideas that form in their minds due to those sensations.
He conceived ideology as a liberal philosophy that would defend individual liberty, property, free markets, and constitutional limits on state power. He argues that, among these aspects, ideology is the most generic term because the 'science of ideas' also contains the study of their expression and deduction. The coup that overthrew Maximilien Robespierre allowed Tracy to pursue his work. Tracy reacted to the terroristic phase of the revolution (during the Napoleonic regime) by trying to work out a rational system of ideas to oppose the irrational mob impulses that had nearly destroyed him.
