Francis Crick, one of the premier biologists of the 20th century, passed away July 28, 2004, in San Diego. On his 88th birthday, I brought him chocolates and spent the day with him in his home in La Jolla.

To the extent that consciousness is useful, it is useful in small quantities, and for very particular kinds of tasks. It's easy to understand why you would not want to be consciously aware of the intricacies of your muscle movement, but this can be less intuitive when applied to your perceptions, thoughts, and beliefs, which are also final products of…