An ideology is a set of aims and ideas, especially in politics. An ideology can be thought of as a comprehensive vision, as a way of looking at things (compare Weltanschauung), as in common sense (see Ideology in everyday society below) and several philosophical tendencies (see Political ideologies), or a set of ideas proposed by the dominant class of a society to all members of this society. The main purpose behind an ideology is to offer change in society, and adherence to a set of ideals where conformity already exists, through a normative thought process. Ideologies are systems of abstract thought (as opposed to mere ideation) applied to public matters and thus make this concept central to politics. Implicitly every political tendency entails an ideology whether or not it is propounded as an explicit system of thought.

(For the Marxist definition of ideology, see Ideology as an instrument of social reproduction below.)

History of the concept of ideology

The term was born in the highly controversial philosophical and political debates and fights of the French Revolution and acquired several other meanings from the early days of the First French Empire to nowadays. The word ideology was coined by Destutt de Tracy in 1796 assembling the parts idea (near to the Lockean sense) and -logy. He used it to refer to one aspect of his "science of ideas". (To the study itself, not the subject of the study.) He separated three aspects, namely: ideology, general grammar and logic, considering respectively the subject, the means and the reason of this science. 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.

According to Karl Mannheim's historical reconstruction of the meaning-shifts of ideology, the modern meaning of the word ideology was born when Napoleon Bonaparte (as a politician) used it in an abusive way against "the ideologues" (a group which includedFact: date=June 2008 Cabanis, Condorcet, Constant, Daunou, Say, Madame de Staël and Tracy), to express the pettiness of his (liberal republican) political opponents.

Perhaps the most accessible source for the near-original meaning of ideology is Hippolyte Taine's work on the Ancien Regime (first volume of "Origins of Contemporary France"). He describes ideology as rather like teaching philosophy by the Socratic method, but without extending the vocabulary beyond what the general reader already possessed, and without the examples from observation that practical science would require. Taine identifies it not just with Destutt de Tracy, but also with his milieu, and includes Condillac as one of its precursors. (Tracy read the works of Locke and Condillac while he was imprisoned during the Reign of Terror.)