“Nighttime walk on a clear night,” journalist and novelist Jan Morris wrote in her diary when she was ninety-three, “Is one of the largest experiences one can have." The mind throws itself back to the giant space that is memory. I imagine neurologist and author Oliver Sacks (July 9, 1933 – August 30, 2015) walking thus as he reflected on his life in various essays written and rewritten in his last two years on earth.

Part memoir, partly collected reflections at the end of a life fully lived, Gratitude contains the crucial things that stand apart as Sacks nears the end of his life.

Last night I dreamed about mercury—huge, shining globules of quicksilver rising and falling. Mercury is element number 80, and my dream is a reminder that on Tuesday, I will be eighty myself.

Elements and birthdays have been intertwined for me since boyhood when I learned about atomic numbers. At eleven, I could say, "I am sodium" {element 11}, and now at seventy-nine, I am gold. A few years ago, when I gave a friend a bottle of mercury for his eightieth birthday - a special bottled that could neither leak nor break - he gave me a peculiar look, but later sent me a charming letter in which he joked, "I take a little every morning for my health."
From "Mercury," written July 2013

Using found items, photographer Paulette Tavormina creates tableaus of mortality. In her Vanitas series, the artist cultivates life and death simultaneously using found objects. Courtesy of the Robert Mann Gallery.

A man who claimed he is "equally drawn to the scientific and the romantic" in humanity is quick to see both in himself. In his own inimical, casual way, Sacks maneuvers us through "what is meant by living a good and worthwhile life." Concepts include injected breaks and pause, reflections on loyalty and commitment, and cherishing the precious things we keep nearby. Roman Emperor Marcus Aurelius wrote in his Meditations about living a universe-worthy life. Sacks sums up the components of his life in front of us to bestow insight into how they form the man.

I am grateful that I have experienced many things - some wonderful, some horrible-and that I have been able to write a dozen books, to receive innumerable letters from friends, colleagues, and readers, and to enjoy what Nathanial Hawthorne called " an intercourse with the world." I am sorry I have wasted {and still waste} so much time, I am sorry to be agonizingly shy at eighty as I was at twenty, I am sorry that I speak no languages but my mother tongue and that I have not traveled or experienced other cultures as widely as I should have done.
FROM "MERCURY," written JULY 2013

The relaxing habit of rock collecting. "I have tended since early boyhood to deal with loss—losing people dear to me—by turning to the nonhuman," wrote Sacks of his rock collection. Photograph by Ellen Vrana.

"A few weeks ago, in the country, far from the lights of the city, I saw the entire sky "powdered with stars" {in Milton's words} such a sky, I imagined, could only be seen only on the high, dry plateaus like that of Atacama in Chile (where some of the world's most powerful telescopes are}. It was this celestial splendor that suddenly made me realize how little time, how little life, I had left. My sense of the heaven's beauty, of eternity, was inseparably mixed for me with a sense of transience - and death. I told my friends Kate and Allen, "I would like to see such a sky again when I am dying."  "We'll wheel you outside," they said.
From "My Periodic Table" written July 2015

Sacks ruminates on friends—including biologists Francis Crick and W. H. Auden—and writes about being loyal to a necessary Sabbath. The Sabbath was a practice that rose from Sack's Orthodox Jewish childhood (although he rejected the religion as an adult for its cruel hypocrisy towards his homosexuality) and came to mean life's most essential rest. His last essay, "Sabbath," was published two weeks before Sacks' death.

The peace of the Sabbath, of a stopped world, a time outside time, was palpable, infused everything, and I found myself drenched with a wistfulness, something akin to nostalgia, wondering what if: What if A and B and C had been different. What sort of person might I have been? What sort of life might I have lived?

I felt I had to be equally open about my cancer - and facing death. And now, weak, short of breath, my once firm muscles melted away by cancer, I find my thoughts, increasingly, not on the supernatural or spiritual but on what is meant by living a good and worthwhile life - achieving a sense of peace within oneself I find my thoughts drifting to the Sabbath, the day of rest, the seventh day of the week, and perhaps the seventh day of one's life as well.From "Sabbath" written July, 2015

In his reclamation of words, Consolations, poet David Whyte defines gratitude as arising from paying attention, from "being awake in the presence of everything that lives within and without us."

Sacks' Gratitude, similarly, is a warm extension of the essential parts of a man who, despite a terminal cancer prognosis, finds joy and peace in remembering a life fully lived and a need to "work until the end." I applaud late-in-life industriousness because I wish it for myself. Like English gardener Gertrude Jekyll, who kept her gardens—and wrote books—long after her sight failed her. Like critic Christopher Hitchens, who journaled his quick step to death, not because it would thrust more life his way, but because it was what he had always done.

At nearly eighty, with a scattering of medical and surgical problems, none disabling, I feel glad to be alive—' I'm glad I'm not dead!' sometimes bursts out of me when the weather is perfect.
FROM "MERCURY," WRITTEN JULY 2013

 Oliver Sacks, 1956.

The pure joy that sparks from Sacks's writing, like struck flint, will pierce and warm your heart. Like Maya Angelou, who welcomed a long march of tomorrows in her early eighties, Sacks demonstrates our ability to live, regardless of age or prognosis.

My father, who lived to ninety-four, often said that the eighties had been one of the most enjoyable decades of his life. He felt, as I begin to feel, not a shrinking but an enlargement of mental life and perspective. One has had a long experience of life, not only one's own life but others' too. One has seen triumphs and tragedies, booms and busts, revolutions and wars, great achievements, and deep ambiguities. One has seen grand theories rise, only to be toppled by stubborn facts. One is more conscious of transcience and, perhaps, of beauty. At eighty, one can take a long view and have a vivid, lived sense of history not possible at an earlier age. I can imagine, feel in my bones, what a century is like.
FROM "MERCURY," WRITTEN JULY 2013

Many writers and thinkers have gifted us with written views from the purple-shadowed lands, including British novelist Penelope Lively's thoughtful reflections on memory and Leonard Cohen's collection of mournful, hopeful poems in his Book of Longing.

Illustration by Leonard Cohen from his Book of Longing.

Wislawa Szymborska's last collection of poetry, published before her death, is a handsome companion to any thoughts on the reckoning of life. In Here, the Polish poet and Nobel laureate plays with time, memory, and meaning.

For all these individuals, Sacks especially, life abounds.