In social studies, a political ideology is a certain set of ethical ideals, principles, doctrines, myths or symbols of a social movement, institution, class or large group that explains how society should work and offers some political and cultural blueprint for a certain social order. A political ideology largely concerns itself with how to allocate power and to what ends it should be used. Some political parties follow a certain ideology very closely while others may take broad inspiration from a group of related ideologies without specifically embracing any one of them. The popularity of an ideology is in part due to the influence of moral entrepreneurs, who sometimes act in their own interests. Political ideologies have two dimensions:
An ideology is a collection of ideas. Typically, each ideology contains certain ideas on what it considers to be the best form of government (e.g. democracy or autocracy) and the best economic system (e.g. capitalism or socialism). Sometimes the same word is used to identify both an ideology and one of its main ideas. For instance, "socialism" may refer to an economic system, or it may refer to an ideology which supports that economic system. Political ideology is a term fraught with problems, having been called "the most elusive concept in the whole of social science". However, ideologies tend to identify themselves by their position on the political spectrum (such as the left, the centre or the right), though this is very often controversial. Finally, ideologies can be distinguished from political strategies (e.g. populism) and from single issues that a party may be built around (e.g. opposition to European integration or the legalization of marijuana). There are several studies that show that political ideology is heritable within families.
The following list is strictly alphabetical and attempts to divide the ideologies found in practical political life into a number of groups and each group contains ideologies that are related to each other. The headers refer to names of the best-known ideologies in each group. The names of the headers do not necessarily imply some hierarchical order or that one ideology evolved out of the other. They are merely noting that the ideologies in question are practically, historically and ideologically related to each other. One ideology can belong to several groups and there is sometimes considerable overlap between related ideologies. The meaning of a political label can also differ between countries and that parties often subscribe to a combination of ideologies.