William H. Calvin (born April 30, 1939) is an American theoretical neurophysiologist and professor at the University of Washington in Seattle.

In his research monograph The Cerebral Code, Calvin suggests that the pattern of action potentials in any particular neocortical minicolumn can be replicated and spread through the cortex like a piece of software code and be "played" on the millions of other minicolumns in the same way one can play a million copies of a compact disc (CD) on a million CD players – the key difference being that while all CD players are designed to do basically the same task, the various cortical minicolumns can all have their own unique "ruts" and the copies of the firing patterns are not exact duplicates.

This allows for a "cerebral symphony" rather than just a million-fold amplification of the same tune and a "survival of the fittest" process whereby those firing patterns that resonate best with the existing pool of "ruts" will dominate one's consciousness and generate intelligent behavior ("Our long train of connected thoughts is why our consciousness is so different from what came before.").

Ethics are possible only because of a human level of ability to speculate, judge quality, and modify our possible actions accordingly."

William H. Calvin has advanced the view that use of the Acheulean hand axe in hominids was a major factor in the evolution in human intelligence.