Ideology is an economizing device by which individuals come to terms with their environment and are provided with a “world view” so that the decision-making process is simplified.Some reactions. First, this definition implies that having an ideology (though not necessarily any ideology) is rational. A normal human being cannot possibly comprehend the bewildering array of things he perceives in the world without some kind of filter to make sense of it all. There is simply too much data, and the world is simply too complicated. Abstraction – multiple layers of it – is necessary to function in a complex world.
Second, an effective ideology will necessarily fail to explain some aspects of the world accurately. The act of abstraction typically involves focusing on identified salient features of a situation or situations, while deliberately ignoring others. This is what makes a model tractable; it is the reason economists adopt models with assumptions sometimes notably at odds with reality. If you try too hard to make your initial assumptions comprehensive, you will find yourself unable to “solve” the model and make predictions. Yet any model that is not comprehensive – that does not account for every variable or exception or special case – will have blind spots. (For more along these lines, see my article with Roger Koppl on “Rational-Choice Hermeneutics.”) This is not an argument against modeling, and it is not an argument against ideology.
Third, an ideology, like any model, should be subject to testing. But what sort of testing is appropriate? One difficulty is that unless your ideology is subject to modification at the margin, a sufficiently robust refutation means altering your whole world view. (Think of the former Christian who, once having been persuaded of the non-existence of god, finds himself unmoored and unable to deal with the world.) In Kuhnian terms, an ideology is more like a scientific paradigm than a scientific theory; sometimes a new paradigm is required, but people invested in the old paradigm will be resistant to a revolution in thinking.
Fourth, even if someone’s ideology is subject to marginal change, for most people the relevant form of testing is poor results in their personal lives. Yet some aspects of one’s ideology – politics especially – are unlikely to have strong personal effects. Your goofy political views probably won’t stop you from getting a job, unless your zealous proselytizing turns off your boss and coworkers. As a result, we shouldn’t be surprised to see little alteration of people’s ideologies on those fronts relating to matters of great public but little private consequence. (For more on this, see Bryan Caplan’s article on “Rational Irrationality.”) The persistence of unsophisticated ideological views on such matters should be no great surprise.