Properly speaking, a liberal is someone who regards freedom of the individual as the main — or only — social good. In other words, liberals think the purpose of government is to protect the freedom of individuals. Liberals understand freedom “negatively”, as the absence of external obstacles to doing whatever you want. This concept of freedom was famously expressed by Hobbes: “a free man is he that in those things which by his strength and wit he is able to do is not hindered to do what he hath the will to do”. In other words, according to the liberal tradition of Hobbes, you’re free as long as nothing external is stopping you doing what you want to do. According to the contrasting “positive” concept of freedom, being truly free means something like “wanting the right things”, if that makes any sense. To find out more, try reading Rousseau.
Since thinking freely, thinking aloud, gaining knowledge, creating and enjoying art, religious observances (etc.) are so vital to human life, liberals strongly support freedom of thought and expression. Anyone hostile to the expression of “impure” thoughts cannot be a liberal in the proper sense of the word. Limiting the expression of such thoughts or enforcing rules against “offensive” speech are the activities of anti-liberal puritans rather than liberals.
Typically, liberals think “freedom for the pike is death for the minnows”, so protecting the freedom of minnows entails putting limits on the freedom of pikes. This can emerge in fiscal policy, for example, when liberals demand heavy taxes of richer individuals to provide free education or health care for poorer individuals. So liberals tend to be “left wing”, although clear-thinking liberals do not regard equality as valuable in itself. Ironing out some extreme inequalities is more the unintended by-product of enhancing the freedom of poorer individuals, which only comes at the cost of limiting some freedoms of richer individuals. This is only justifiable as long as there is an overall enhancement of freedom.
So much for liberalism. What about conservatism? Properly speaking, a conservative is someone who takes a cautious approach to political change. Conservatives do not oppose change per se: in Burke’s words, “a state without the means of some change is without the means of its conservation.” Conservatives often welcome newer arrangements, but they always strive to keep what we know works tolerably well (or even tolerably badly, as long as it’s tolerable). Conservatives are above all sceptical pragmatists rather than convinced radicals. They don’t think anyone knows enough about society to justify root-and-branch reform of the sort attempted in political revolutions. These revolutions are usually bloody, and the changes they bring are rarely for the better, although the people who bring them about always write about them in glowing, euphemistic terms.
It is a pity that so much political discourse assumes liberalism and conservatism are opposed to each other. Liberals and conservatives are often supposed to be rivals, or even enemies. But really, they just emphasize one or the other of two essential components of thought. The necessity of both components is perhaps most obvious in the growth of scientific knowledge. On the one hand, we need new ideas and playful thinking; on the other hand, we cannot accept ideas that contradict what we believe already. So science proceeds by means of both a free-thinking liberalism and a cautious conservatism. Science needs sometimes nutty experimentation and wild theorizing, as well as careful observation, testing, and the judicious application of logic. The latter essentially involves accepting a new idea only if it fits with what we know works already. This insistence on a good “fit” gives us a preference for modest rather than extravagant theory, simple rather than complicated theory, and so on.
Interestingly, this conservative principle in science is an essential ingredient in the lead-up to a scientific revolution. Over the course of a theory’s growth, anomalies build up, like pressures between tectonic plates, to the point where “something’s gotta give” and an intellectual earthquake occurs. Those pressures can only build up where change is resisted — in Thomas Kuhn’s terminology, where a “paradigm” is clung to, often with grim, partisan determination. In the end, change cannot be avoided any longer, and it is dramatic and precipitous. Scientific revolutions are often bad-tempered, but they are never literally bloody like political revolutions, and they nearly always do a lot of good, because they involve the adoption of completely new and better ways of looking at things. No one loses their life in a scientific revolution, although some lose their jobs.
One of the most important aspects of conservatism is its rejection of “foundations” or basic principles. Conservatism is thus opposed to radicalism rather than liberalism, where radicalism supposes that the goodness or badness of a political system depends on a small set of basic principles. Typically, political radicals think “the system” is irredeemably flawed because it has some basic injustice built into its foundations. The cure, radicals suppose, is a revolution that will change everything from the bottom up, starting at the foundations and going all the way to the top of the edifice. Alas, human nature being what it is, radical attempts to change everything usually end up where you get to “meet the new boss / same as the old boss”.
The dominant conservative metaphor for knowledge (political or otherwise) is not that of a building resting on a foundation of basic principles, but rather of a web anchored at various points to the real world. These points inevitably change as circumstances change, and the web itself is an “organic”, evolving thing. The repairs are ongoing, piecemeal, and have to be made without “stepping off” the web. The role of circumstances is important here. Conservatives appeal to particular circumstances rather than to general principles when trying to work out what is for the best. As Burke put it: “Circumstances (which with some gentlemen pass for nothing) give in reality to every political principle its distinguishing colour and discriminating effect. The circumstances are what render every civil and political scheme beneficial or noxious to mankind.”
There seems to have been a remarkable mutual admiration and intellectual agreement between Burke and Adam Smith. Both had a wide liberal streak, as do almost all present-day libertarians. However, something intrigues me in present-day libertarianism, which often appeals to basic principles. Although present-day libertarians often describe themselves as “conservative”, I suspect that many of them are more radical than conservative. The urge to change the entire system from the bottom up isn’t just found among “anti-capitalist” socialists, but also among some “pro-capitalist” anarchists!