[Aldous Huxley] compared the brain to a 'reducing valve'. In ordinary perception, the senses send an overwhelming flood of information to the brain, which the brain then filters down to a trickle it can manage for the purpose of survival in a highly competitive world. Man has become so rational, so utilitarian, that the trickle becomes most pale and thin. It is efficient, for mere survival, but it screens out the most wondrous part of man's potential experience without his even knowing it. We're shut off from our own world.