An ieology is an organized collection of ideas. The word ideology was coined by Destutt de Tracy in 1796 (during the French Revolution) to define a "science of ideas". 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 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.