The Astonishing Hypothesis

Thanks to Phil Krause for suggesting this post.

francis_crickThe Astonishing Hypothesis is a 1994 book by scientist Francis Crick about consciousness. Crick, one of the co-discoverers of the molecular structure of DNA, 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 according to Crick 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 led to acceptance of consciousness, free will, and the human soul as subjects for scientific investigation.

the_astonishing_hypothesiscoverRather than attempting to cover all the aspects of consciousness (self-awareness, thought, imagination, perception, etc.), Crick focuses on the primate visual system and breaks down the prerequisites for conscious experience into several broad subconditons, including some sort of short term memory and attention mechanism. The book then delves into a brief overview of many neuroscientific topics, ranging from a survey of how neurons function to a description of basic neural circuits and their artificial equivalents. Throughout, Crick cites various experiments which illustrate the narrow points he is making about visual awareness, such as studies investigating the phenomenon of blindsight in macaques.

The later chapters of the book try to synthesize many of the points made earlier about the visual system into a unified framework, although Crick frequently notes the many exceptions to his assumptions and the clumsiness of many of his attempts at synthesis. Also, here he takes the opportunity to make suggestions for further experiments that could provide empirical basis for further understanding about human consciousness and includes a brief addendum on several topics he purposefully glossed over, like free will. Overall, the message Crick repeats as the main purpose of writing the Astonishing Hypothesis is to break the scientific community’s reluctance to give consciousness a thorough and scientifically-grounded investigation, and to encourage others such as philosophers to address the issues of consciousness in a way that takes account of neuroscientific discoveries.

For background and criticism: The Astonishing Hypothesis

This entry was posted in Neuroscience. Bookmark the permalink.