THE RIVER OF CONSCIOUSNESS

Fans of the late neurologist have another chance to enjoy this erudite, compassionate storyteller, essayist, and memoirist in what may be his final work.

This collection of 10 essays, some of which appeared previously in the New York Review of Books, was assembled by three colleagues from an outline provided by Sacks (Gratitude, 2015, etc.) two weeks before his death in 2015. Here, the author explores evolution, time, memory and forgetting, experience, creativity, and consciousness. As his colleagues note, Sacks “interrogates the nature not only of human experience but of all life (including botanical life).” Readers will see how Darwin’s botanical work provided the strongest evidence for evolution and natural selection, the different ways in which time is perceived and experienced, and the fallibility of memory (explored in a fascinating piece on cryptomnesia, or unconscious plagiarism). The essay on misheard words, a real problem for the aging Sacks, is the shortest entry and also the funniest. The most speculative is “Scotoma,” a neurological term for a disconnect in perception, which Sacks uses to refer to the neglect or oversight of an idea proposed or a discovery made before its time. This gives the author the chance to explore how the history of science might have been different. The longest, densest, and most technically demanding is the title essay, “The River of Consciousness,” in which Sacks examines what neuroscientists have begun to learn about the neural basis of consciousness, from relatively simple mechanisms such as perception to more complex issues such as memory, imagery, and reflection. Interestingly, the collection can be seen as a subtle reminder of this polymath’s previous works, for references to a number of these appear throughout the text and in footnotes.

A collection of dissimilar pieces that reveal the scope of the author’s interests—sometimes challenging, always rewarding.