The Astonishing Hypothesis [1] is a 1994 book by scientist Francis Crick about consciousness. Crick, one of the co-discoverers of the molecular structure of DNA in 1953, later became a theorist for neurobiology and the study of the brain. The Astonishing Hypothesis is mostly concerned with establishing a basis for scientific study of consciousness; however, Crick places the study of consciousness within a larger social context. Human consciousness is central to human existence and so scientists find themselves approaching topics traditionally left to philosophy and religion.
The Astonishing Hypothesis posits that "a person's mental activities are entirely due to the behavior of nerve cells, glial cells, and the atoms, ions, and molecules that make them up and influence them." Crick claims that scientific study of the brain during the 20th century lead to acceptance of consciousness, free will, and the human soul as subjects for scientific investigation.
Public perceptions of science and the questions that scientists are willing to ask are strongly influenced by religion. Crick had discussed the relationship between science and religion in his earlier book What Mad Pursuit. Crick's view of this relationship was that religions can be wrong about scientific matters and that part of what science does is to confront the errors that exist within religious traditions. For example, the idea of a mechanism for the evolution of life by natural selection conflicts with some views on creation of life by divine intervention. Crick's subtitle for The Astonishing Hypothesis is The Scientific Search For The Soul. Crick argued that traditional conceptualizations of the soul as a non-material being must be replaced by a materialistic understanding of how the brain produces mind. The publicity generated by opposition to scientific ideas such as natural selection or the scientific study of the soul brings such topics into more widespread debate.
In his book, Crick presents an idea that has great potential to provoke widespread public discussion and opposition. The 1990s were declared the Decade of the Brain. Within the brain science community, researchers began discovering mechanisms of brain function that Crick claims can account for the human soul.
In his review of Crick's book, J. J. Hopfield (Science magazine, 4 February 1994) concluded that, "The book should be read by scientists for its eloquent attempt to put consciousness, which we so much equate with the essence of our humanity, into the realm of science."
Crick's controversial message, "You, your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behaviour of a vast assembly of nerve cells and their associated molecules" [2] has caused some controversy over the physiological approach.