With the longest presidential campaign in history rolling along, we are going to hear the term "flip-flop" a lot. Mitt Romney will make certain of that. Now in it's original incarnation, the concept was sound enough. If a candidate holds one position, then flips to the opposite position, and then flops back to his original, all with politically expedient timing, we have good reason to doubt his integrity, and even his intelligence. Constantly shifting opinions is not the sign of a sound and strong mind.
However, that doesn't mean change is bad per se. If we look at the intellectual development of cultures, mankind as whole, or even our personal lives, we see a pattern of accumulated information, with occasional changes of opinion as we learn. Complete stagnation of views is a rarity, at least in a sound mind and a flourishing society. In addition, the world itself keeps changing, so what was true about our world 200 years ago might not be true now (eg the importance of horsemanship).
So change is good, periodically. This is a concept that I think suffers from the way most religious views are taught to children. We are told truth is absolute, unchanging, handed down complete and perfect from on high. But of course even religious absolutes change over time, as the Pope recently demonstrated yet again. History has been unkind to completely static absolute views.
Science has fared much better than absolutism. In science, theories are often incomplete, and find themselves supplanted over time. The medevil notion of impetus was replaced with Newtonian physics, which was in turn supplanted by relativistic physics. The earth was thought flat, then spherical, then slightly oblate. In each case, the revisions improved on what came before, as opposed to reversing prior knowledge. It is too blunt to say they were always wrong. Right and wrong are relative. Step by step, bit by bit, we get at reality, and our confidence in what we know increases. Some things we know very certainly, some somewhat certainly, some with serious reservations or limitations.
Yet certainty is what America seems to want. Now it is not necessary for a politician to change his view and back again to be called a flip flopper. Now, any change at all is viewed as a negative, and Jim Gilmore has the audacity to parade his lack of change of any views ever as some sort of virtrue! Sorry folks, if you haven't changed your opinion of anything in 20 years, that just means you have stopped thinking.
With critics of science it can be even worse. Scientists discover so many asteroids and other celestial bodies that it makes little sense to group Pluto with the other planets, and instead it is changed to the status of Dwarf Planet. Yet what should have been celebrated as progress for scientific knowledge was derided as implying that scientists can't get anything right. Are you serious, as you talk into your cell phone and eat from your microwave while reading your email rigth before you take your sleep medication?
In the evolution/creation debate, the creationists/IDers love to jump on any scientific revision as a sign of weakness, as they stand cemented to a flawed view. Here you can see my favorite pair of creationist goofballs, Comfort and Cameron, pretending that the way to find out what scientists think about evolution is to interview people on the street. They also deride the use of terms like "we surmise", "maybe", "could've", and "possibly" as signs of evidenciary weakness, when they are really just the objective terms one uses when describing imperfect knowledge. Cameron and Comfort don't recognize anything except perfect knowledge and none at all. I leave it as an exercise for the reader to decide which it is for them.
Knowledge is not handed down from on high complete and perfect as the Camerons and Comforts and Falwells of the world would have you believe. Hardworking, brilliant people do good science and gain imperfect information bit by little bit. The demand for absolute knowledge and opinions that never change is unrealistic. Want to see a world based on that? Look to the Middle East. That's the big dirty secret in this culture war we find ourselves in with people in the Middle East: that the epistemological view of people like Cameron and Comfort and Falwell is a lot more like those of your average radical Middle Eastern Muslim than it is like a scientist like Richard Dawkins or Ken Miller. We should hold ourselves to a higher standard, as well as our politicians and scientists.