Even while it's true that we are tied to our molecules and proteins and neurons - as strokes and hormones and drugs and microorganisms indisputably tell us - it does not logically follow that humans are best described only as pieces and parts.

The continuous networks of neural circuitry accomplish their functions using multiple, independently discovered strategies. The brain lends itself well to the complexity of the world, but poorly to clear-cut cartography.

Just like a good drama, the human brain runs on conflict.

As Walt Whitman correctly surmised, we are large and we harbor multitudes within us. And those multitudes are locked in chronic battle. There is an ongoing conversation among the different factions in your brain, each competing to control the single output channel of your behavior. As a result, you can accomplish the strange feats of arguing with yourself, cursing at yourself, and cajoling yourself to do something - feats that modern computers simply do not do.

If choices and decisions derive from hidden mental processes, then free choice is either an illusion or, at minimum, more tightly constrained than previously considered.

If our brains were simple enough to be understood, we wouldn't be smart enough to understand them.

As we develop better technologies for probing the brain, we detect more problems.