“David Hume referred to causality as ‘the cement of the universe.’ He was being ironic, since he knew that this so-called cement was a hallucination, a tale we tell ourselves to make sense of events and observations. No matter how precisely we knew a given system, Hume realized, its underlying causes would always remain mysterious, shadowed by error bars and uncertainty. Although the scientific process tries to make sense of problems by isolating every variable–imagining a blood vessel, say, if HDL alone were raised–reality doesn’t work like that. Instead, we live in a world in which everything is knotted together, an impregnable tangle of causes and effects. Even when a system is dissected into its basic parts, those parts are still influenced by a whirligig of forces we can’t understand or haven’t considered or don’t think matter. Hamlet was right: There really are more things in heaven and Earth than are dreamt of in our philosophy.”
–Jonah Lehrer. “Trials and Errors.” Wired Jan. 2012: 102-109. Quote on page 109.