An awareness of how language is able to reinforce and maintain certain key values and attitudes - and through this to support existing power structures within our society - is important; and it provides you with a very useful subtle tool when analysing texts. Also, because this is such a subtle level of analysis, it can easily lead to far higher marks being awarded. It is an advanced idea, for sure, but worthy of consideration even if you are not yet studying A-levels.
An ideology is any one of the many ideas that we all share - at least if we belong to a similar culture or society. Properly speaking, these shared ideas are termed dominant ideologies.
An example of a current dominant ideology is the belief that if you can afford to buy say, a luxury yacht, then you should be free to spend that money any way you choose. But, of course, some people might rightly believe that there are many people in society who work very hard indeed and yet would never be able to afford such a luxury as a yacht. They might say that the wealth generated within society should be more fairly shared between the so-called 'haves' and the 'have nots'. They might worry too that the power that can be wielded by someone who is wealthy enough to own a yacht is far in excess of the power that could be wielded by a poor person.
Importantly for your course, language can easily be used by an author in ways that hide the ideologies it acts to reinforce or maintain. The older the piece of writing, the more obvious will be its ideological content. Writing from the nineteenth century, for example, very much treated women as very different from men in what roles they were expected to take in life. Looking out for the ways in which writing acts to reinforce and maintain society's dominant ideologies can be a subtle technique and is always well rewarded by the examiner.
You will see by now that ideologies change as society changes and also how politics rapidly becomes involved in any definition of ideology. In fact, the very idea of dominant ideology has its roots in politics and philosophy. Way back in 1867, the political philosopher Karl Marx published his highly influential ideas about how the direction he felt that human societies were developing. He decided that the hierarchical nature of societies was linked directly to what he called 'the means of production'. Marx felt he could show how a society tended to be led by those in power who exploited those not in power for their own ends. He believed that all of society's dominant ideologies tended to work to favour the 'haves' (whom he called the bourgeoisie, i.e. the owners of production - those in power) as against the 'have nots', whom he called the proletariat - those without power. He also felt that the ideologies worked to keep the power balance in society pretty much constant. He called this society's status quo.
It's important to recognise that Marx was reacting to what he was observing in mid- to late-19th century northern England. This was a rapidly industrialising society that was deeply split between the 'haves' and the 'have nots'. The political system operating then was - as now - called capitalism. In a capitalist society people are able to borrow and invest money freely and to make and sell goods for profit - employing and sacking workers as required at whatever wage is deemed competitive by the owner or by market conditions.
Marx felt strongly that one way the bourgeoisie unfairly exploited the proletariat was to create conditions (through education, religion, family the mass media, police, laws, etc.) that meant the proletariat were unable to recognise - or at least unable to affect - the unfairness of their society's power hierarchies; in fact, Marx felt that ideologies that helped keep people in their place were seen to be ideas that were entirely natural or, even, God given - they were 'the way things are meant to be'.
The core of Marx's belief was that all societies naturally evolve because of pressures brought about by economic forces. He claimed to have seen a clear historical evolution from early societies based upon primitive tribalism, through to the feudalism of the Middle Ages on to present day capitalism. Crucially, he saw the next movement to be to a fairer society based on socialism which would finally lead to an ideal, enlightened social system which he called communism. In a communist society, Marx thought that the inhabitants would delight in equality and co-operation, basing there society on the guiding principal of 'from everyone according to his abilities, to each according to his needs'.
Today, Marxists see an important ideology as our society's belief that it is perfectly acceptable and normal, for example, to want to acquire material goods. This is a dominant ideology called consumerism. Marxists, however, would argue that we are all so heavily focused on this way of thinking, that we fail to recognise or care about the power and corruption that exists within our society and wider world, or the pollution created by such rampant consumerism.
For a much fuller explanation of this fascinating and useful area of study click here.