I was in the Sistine Chapel chapel a few weeks ago. The last time I was there, I was a skeptical, quasi-believer. I wondered how the experience would change given my current atheism.
It was still a moving experience despite the crowds. However, I did have one new insight.
As most people are aware, the famous picture of God touching Adam's finger is full of symbolic meaning. The arrangement of God and his angels perfectly maps out the shape of the human brain. Michelangelo was quite knowledgeable about human anatomy (he dissected corpses to better understand human skeletal structures, musculature, etc.) Thus, it is fairly certain that Michelangelo was intentionally depicting the brain.
The bigger, unanswered question is what point Michelangelo was attempting to make. Was he simply representing the entry of the human spirit into Adam, which was symbolized by the brain, believed at the time to be the seat of intelligence?
The new insight and interpretation I now favor was that Michelangelo was trying to tell everyone that it is "all in your head."