A liberal is someone who believes in individual rights and choice, limited government under the rule of law, and the possibility of incremental individual and social progress, viewing social programs (as Mill and Popper did) as experiments in problem-solving to be evaluated empirically. The overall size of government matters less than the actual policies, though many "classical" liberals (especially libertarians) believe that a smaller government will tend to yield fewer "government failures."(Sources: Various)
[NB. Strict libertarians might merit their own heading because, unlike virtually all liberals, they are not welfare-consequentialists; the only function they seek to maximize is individual freedom. This is a position they hold in common with anarchists, who are more properly designated as radicals, mainly because of what they are willing to do to achieve their desired outcome.]
A liberal position on eggs and omelettes: It is sometimes worth breaking a few eggs to make a tasty omelette; but omelettes sometimes turn out badly. Try to make only good omelettes, and avoid making a particular bad omelette more than once.
A conservative is someone who believes in individual rights and choice but constrained by larger social structures that provide order via law, culture, religion, and traditions. The status quo is likely preferable to even incremental change, though changing circumstances do sometimes require slight adjustments to the social order. The main job of government is maintenance of the social order. (Sources: Scruton, Oakeshott and others)
A conservative position on eggs and omelettes: Better to keep the eggs we already have than waste them making an omelette that probably will turn out badly, especially if it is not a traditional part of our cuisine.
A radical is someone who believes the current social order is vastly inferior to some conceivable society, usually Utopian in conception. They believe in large-scale and rapid policy changes on the understanding that those changes inevitably will improve on the status quo. They believe in social welfare, but are convinced they, the vanguard party, are the only ones who know how to maximize it. (Source: Marx and others)
A radical position on eggs and omelettes: We should break as many eggs as necessary to make an omelette that, as an irrebuttable presumption, will be wonderful, even if no one has ever before made such an omelette. The distribution of the omelette will be according to need, as determined by "Central Board of Omelette Distribution."
A reactionary is someone who believes the current social order is far worse than some mythic preexisting social order to which we should return, regardless of cost. What is "better" is what was. And it has little or nothing to do with overall social welfare. The reactionary vanguard knows what is best, based on folk myths. (Sources: Various fascists, white supremacists, etc.)
A reactionary position on eggs and omelettes: Life was so much better before our folk started, under the influence of "others," breaking eggs to make omelettes. We must purge such foreign influences. Our pure and homogeneous forebears, who were the best folk, ate only raw eggs, so that's what we must do. And, by all means, make sure they are all white eggs.