THAT ONE FIRM POINT
Give me one firm point (for my levers and pulleys), said Archimedes, and I'll unhinge the Earth. And he proceeded to demonstrate the principle by moving a heavy boat, laden with sailors, off the drydock.
Granted, Archimedes' fulcrum serves only as a metaphor here for the one firm center from which to measure and judge. But the problem is similar for mechanics and metaphysics. Except that, in metaphysics - and in physics as well - the human craves absolutes and isn't getting any.
The human tried to find that one firm point of departure, that one fixed direction, that one absolute among relatives: Geometry, divinity, the North Star, one's own conscious thought (of cogito, ergo sum fame), Nirvana, time and distance - nothing really worked.
Time and distance are relative since Einstein, and thought has become relative, too. Still, like Archimedes and Einstein, humans will continue to think that there is an absolute out there, waiting to be found and followed.