> And high is better than low, because if you have your head down, the blood goes to your brain, because feet stink and hair doesn’t stink as much, because it’s better to climb a tree and pick fruit than end up underground, food for worms, and because you rarely hurt yourself hitting something above—you really have to be in an attic—while you often hurt yourself falling. That’s why up is angelic and down devilish.

You could also argue that because of gravity and potential energy, up is usually the result of purposive action and effort, while down is often the result of accident or neglect ("you often hurt yourself falling"). That potential energy (and wide-open space) can also be used for maneuvering, so if two people or other creatures are fighting, one who is higher is generally at an advantage compared to one who is lower or lying on the ground. The lower party has less energy available to direct toward the opponent, and usually less room to move, being more constrained by the presence of the ground.