The deep secret of the brain is that not only the spinal cord but the entire central nervous system works this way: internally generated activity is modulated by sensory input. In this view, the difference between being awake and being asleep is merely that the data coming in from the eyes anchors the perception.

When we're in a human body, we don't care about universal collapse - instead, we care only about a meeting of the eyes, a glimpse of bare flesh, the caressing tones of a loved voice, joy, love, light, the orientation of a house plant, the shade of a paint stroke, the arrangement of hair.

It is the most wondrous thing we have discovered in the universe, and it is us.

This is the hallmark of a robust biological system: political parties can perish in a tragic accident and the society will still run, sometimes with little more than a hiccup to the system. It may be that for every strange clinical case in which brain damage leads to a bizarre change in behavior or perception, there are hundreds of cases in which parts of the brain are damaged with no detectable clinical sign.

Love was not specified in the design of your brain; it is merely an endearing algorithm that freeloads on the leftover processing cycles.

The majority of human beings live their whole lives unaware that they are only seeing a limited cone of vision at any moment.

The first lesson about trusting your senses is: don't. Just because you believe something to be true, just because you know it's true, that doesn't mean it is true.