Some ideologies, such as liberalism, conservatism, and socialism, are complex symbolic structures. Mastering them requires specialization, and because we are all amateurs in almost all symbolically rich domains, most people are not ideologically sophisticated. Instead, they reason about politics in a maturationally natural way, via friend-foe representations and inferences based on those representations (for example, friends of foes are foes). However, even complex ideologies are much simpler than the political, economic, and social systems that they are supposed to represent. Hence, all ideologies are inaccurate to varying degrees. More subtly, all are incomplete in various ways; in particular, they fail to anticipate some crucial events (for example, global warming), which leads to unanticipated value trade-offs and strategic conundrums. Ideologists sometimes adapt to incompleteness via recombinant innovation, producing hybrid ideologies (for example, ecosocialism). In turn, this tends to produce inconsistencies between new and old parts of an ideology. Thus, inaccuracy, incompleteness, and inconsistency are not pathologies of political belief systems. They are the inevitable result of ideologists grappling with a reality that is far more complex than their symbolic constructions can be. Therefore, evaluations of ideologies that identify errors, incompleteness, or inconsistency at a single point in time are often unenlightening. Following Imre Lakatos, evaluations should focus on how a sequence of ideologies—an ideological tradition—evolves.