…Einstein had said, “Evolution has shown that at any given moment out of all conceivable constructions a single one has always proved itself absolutely superior to the rest,” and let it go at that. But to Phaedrus that was an incredibly weak answer. The phrase “at any given moment” really shook him. Did Einstein really mean to state that truth was a function of time? To state that would annihilate the most basic presumption of all science!
But there it was, the whole history of science, a clear story of continuously new and changing explanations of old facts. The time spans of permanence seemed completely random, he could see no order in them. Some scientific truths seemed to last for centuries, others for less than a year. Scientific truth was not dogma, good for eternity, but a temporal quantitative entity that could be studied like anything else.
Robert M. Pirsig, Zen and the Art of Motorcycle Maintenance