When we speak seriously of ideology--of liberalism, conservatism and so forth--we are speaking of a philosophy which addresses fundamental questions about the human condition, and on the basis of the answers it offers to those questions, the problems of economic, political, cultural and social life. Arguably the most important of those questions are:
1. What can we know about the world, and especially the human, social world?
2. What are human beings like--individually and collectively, in society?
3. Given what we know about human beings, what should we consider to be society's goals?
4. If we think that society should be something other than what it is, can we change it for the better? Would the potential gain outweigh the risks?
5. How far can we rely on reason in changing our social arrangements--our economic system, our political system, our culture--for the better?
Conservatism, liberalism, and the rest, all have very specific answers to these questions, which determine their address of specific political questions. For now let us stick with conservatism and liberalism, in the classical sense of each of those terms, which retain some usefulness from this vantage point (even as much else may have changed).
Conservatism takes a dark view of human nature (think Thomas Hobbes), and is pessimistic about the applicability of reason to society. This leaves conservatives more concerned with keeping human badness in check than with, for example, achieving a society affording its members greater freedom, justice or equality, which generally seem to them unrealistic aspirations in the circumstances. Thus they think that the prospects of change for the better are very dim, while tending to regard the social arrangements that have emerged over time, "organically" in response to specific situations--what is often called "tradition," and where following tradition in doctrinaire fashion does not settle the matter, judgments by an elite respectful of tradition based on its own personal, practical experience--as likely to be superior to any human "plan." (As the foundational Joseph de Maistre argued in his
Considerations on France, a person can grow a tree, but they cannot "make" a tree--and so it is with a society in the conservative's view.)
Liberalism takes a different view of these matters, seeing human nature as a broader, more flexible thing than conservatives give it credit for, what they might conceive as a timeless, unchanging, unchangeable (and nasty) human nature substantially formed by circumstances. (The liberal John Locke characterized the human mind as a blank slate at birth in his
Essay on Human Understanding.) They also have a higher opinion of the capacities of human reason--and therefore see room for better, much better, than we have been doing up to this point, and with that, much more scope existing for a freer, fairer world than history has known. Indeed, they may regard the exercise of reason for the sake of creating a better set of social arrangements as not merely desirable and possible, but obligatory, given that their starting point for thought about society is an individual they regard as having inalienable rights, not least to freedom. They may even regard such change as a practical necessity, for their reason tells them time and again that the world changes, and the "old ways" often fail to meet the new demands it throws up. (Consider, for instance, the interrelated matters of nationalism, militarism, war. The conservative does not see such things going away any time soon, but the liberal points to them as having ceased to be tolerable in an age of globalization, and of nuclear weapons.)
Of course, confronted with this tiny, tiny bit of philosophy 101 many snap "People don't use the word like that!" And certainly
most people don't--in part because there has been some awkward shuffling of labels (conservatives having been forced to reckon with liberalism, liberalism having bifurcated into more conservative and more radical versions, etc., etc.) creating a fair amount of superficial confusion. However, more important than any such confusion is the fact that so few thought about the matter long enough to be confused by it; that very few of those who identify as "conservative," "liberal," or anything else have ever considered the questions discussed here at all, let alone in any great depth. All the same, there seem to me to be two rejoinders to their dismissive attitude:
1. Their using the terms in a shallow, unthinking, politically illiterate way does not make those who use the terms in the ways long established in political philosophy and political science somehow incorrect. (To suggest otherwise is more than saying "My ignorance is as good as your knowledge." It is saying "My ignorance is
better than your knowledge.") If anything, there is a far better case for the matter being the other way.
2. The more casual, ill-informed usages often turn out to be more consistent with the deeper ones than people generally realize. While people reduce labels like "conservative" or "liberal" to responses to particular hot-button issues about which they may be speaking emotionally rather than intellectually the conservative or liberal position tends to reflect those deeper philosophical assumptions just discussed here (even where the person in question never considered the issue on that level). Thus does it go with such a matter as gender (e.g. gender roles, gender identity, reproductive rights, sexual freedom), with the conservative inclining to the traditional practice, the liberal or radical seeing more scope and reason for change, on the basis of what they rationally judge to be fair and right, and in line with the demands of human rights, including freedom.
The result is that the vulgarian snapping "People don't use the word like that!" has probably done so plenty of times without even knowing it.