The conceptual difficulty of understanding how consciousness emerges from the brain has a historical analogue in the debate raging in the nineteenth and early twentieth centuries about vitalism and the mechanisms of heredity. The chemical laws underlying heredity were deeply perplexing. How was all the information specifying a unique individual stored in a cell? How was this information copied and passed on to the cell’s descendants? How could the simple molecules known at that time enable the egg to develop into an adult?
