The definition of ideology varies depending on the school of thought. Ideology, according to Louis Althusser, is the imaginary relationship of individuals to their existence or reality. This is different from the Marxist point of view, which postulates that an ideology creates a sense of false consciousness. Although ideologies do not represent the reality, they do represent our social and or imaginary reality. In this regard, ideologies are important because they shape who we are or at least what we believe in. Further, according to Althusser, we are subjected to ideology even before we are born, and it is this ideology that gives us our identity. For instance, in various communities, it is certain even before a child is born that he or she will bear the father’s name, in line with the existing familial ideologies.

The mainstream defines an ideology as “a system of ideas which attempts to explain reality” (Prof. West, Suffolk College). The definition is in agreement with the Marxist point of view that ideologies represent the reality. Further, the reality is almost always biased to support a particular group. In this regard, ideology would not be important in our lives. This is because the powerful will always persuade the masses through false ideologies that entrench their exploitation of that particular group. The argument suggests increased focus on practical considerations instead of ideologies.

Ideologies are belief systems based on ideas and constructs about the world and the people in it. For example, democracy is a political ideology based on the belief that people have the right to choose their leaders, laws, and so on. In terms of political systems, an ideology serves as the basis for how a nation will be governed, which is a fundamental aspect of collective living. 

Ideologies are usually shared between a group of people and serve as the basis for how those people think and behave. Capitalism, for example, is both an economic system and an ideology. Capitalism is a system in which manufacturing and the provision of services is provided by private businesses in exchange for consumer dollars. Yet it is also an ideology because it is undergirded by a particular set of beliefs about how a market economy will operate and to what extent it will intersect with the government or other institutions. For instance, if you live in a capitalistic society, you wouldn't go into a store and try exchange a sheep for a bag of oranges because capitalism dictates that you are expected to pay for the item you desire at the price it is being offered, which is usually in dollars, not sheep.

As for whether we need ideologies in our lives, that is a tricky question. Technically, we need very little to live (food, shelter, water); however, societies probably wouldn't be very successful without ideologies. As previously mentioned, ideologies heavily influence behavior, particularly around what is and isn't acceptable. Given that, it's hard to imagine a society creating laws or social order without an ideology to dictate what's considered right and wrong. So while it is technically possible for people to live without an ideology, it would make life very, very challenging.