Amidst the tug-of-war among various viewpoints, society/government/culture/what-have-you (or any portion of these) will change over time. In retrospect, this necessary/inevitable change is deemed middle-of-the-road (moderate). Those who want to halt this change are deemed conservative (conserving the status quo). Those who want to accelerate change proportionally to how conservatives want to retard it are deemed liberal. Those who want to not just stop the "normal" change but reverse its direction are considered reactionary, and those who want to accelerate the change proportional to that (i.e., a lot) are considered radical. While some are on either the right (conservative/reactionary) or on the left (liberal/radical) side on most or all issues, I wouldn't be surprised to find that most people are on the right on some issues while on the left side on others.

Naturally, the liberals feel they are advocating change for the better, and that it's overdue. Conservatives feel that the change is for the worse, and that it's premature. Moderates feel that things are progressing at an acceptable pace.

I see myself as conservative on gun control (no need for more laws), moderate on environmental concerns (don't want to stop or go back but also don't want to jump into things), liberal on abortion rights (should be less encumbered by legal restrictions), and radical on religion/state (get those prayers out of legislatures and public school games). I'm probably reactionary on some things, but they don't come to mind right now. Overall, I think of myself as conservative-to-moderate.