And historically, we've associated those sides of ourselves with altitude. The more physical, animal urges are often described as low, base or earthy. Our more intellectual and spiritual pursuits are high or lofty. The Western tradition at least puts hell "down below" somewhere, and heaven up above us. Someone with his head in the clouds is quite different from someone with his mind in the gutter. (Of course, we also refer to great thinkers as deep or profound, so go figure.)
I'm thinking about plotting altitude changes over time. As infants, we're pretty focused on input and output ... the bodily basics. We're at the bottom of the graph. As we grow, we learn how to cover those basic needs, and start to think about things like school, friends and TV schedules. Somewhat later, we may develop a social conscience, worrying about wars, the environment and philosophy ... the meaning of life.
We pass that peak, and our concerns turn to entertainment systems, hardwood floors and cleaning products. I'll never forget a shopping trip with a dear friend, one with whom I had shared countless hours of debating politics and discussing philosophy. We were going to change the world, but now he practically lept across the supermarket aisle, exclaiming "Wow! SoftScrub now has bleach!"
And ultimately, we're going to wind up worrying about taking our pills and getting enough fiber. Walking may again become a challenge, and even getting a good night's sleep may be elusive. So maybe the altitude graph looks like a bell curve, starting and ending with bodily functions, and peaking at metaphysics somewhere in the middle.
By the way, a good business model is to package physical basics like food, shelter and clothing as lofty activities like haute cuisine, luxury homes and high fashion. Ever see a bidet?