"Where'd you get that crazy idea?" - my Mother
Where is the line between an idea and reality? Ideas can be very dangerous (Nazism), frivolus (Dadaism), dynamic (capitalism), or just plain peculiar (Flippism). And what about crazes throughout history (tulipmania, hula hoops, pet rocks, the dot-com boom and bust?) The judgement of time may eliminate their importance, but some ideas will survive, mutate, or combine with other ideas.
The most chilling aspect of this process of idea-life is American jurisprudence, which is based more on precedent that on justice or truth. The miscegenation laws (which lasted into the 1970's) were all based on precedent. The current row over same-sex marriages is also based on precedent, both legal and bibilical. Going into the subject further, the very idea of marriage has changed over the millenia, and will no doubt continue to do so.
So where is the truth in all this? Is that an ideal, an unattainable goal, or is it just another idea, one that may also change and mutate over time?