In his last months of life, Oliver Sacks left us with powerful thoughts on death

Oliver Sacks, a world-renowned neurologist and author, died on Sunday Aug. 30 at the age of 82.

When diagnosed with terminal cancer, Dr. Sacks didn't hide away. He opened up and announced his fate in February, beginning a spurt of writing - arguably some of his best work - contemplating life, love, and death.

There is much we can learn from Sacks, from the way he helped humanize often misunderstood people with neurological disorders, cared so deeply for his patients, and pushed the boundaries of neuroscience. But one of his last op-eds for The New York Times, called "My Periodic Table of Elements," is especially memorable. In it, he revealed some of his most profound thoughts on death.

Sacks recounts one night this summer when he traveled far from city lights and saw the whole sky lit up with stars.

"It was this celestial splendor that suddenly made me realize how little time, how little life, I had left," Sacks wrote. "My sense of the heavens' beauty, of eternity, was inseparably mixed for me with a sense of transience - and death."

Despite the outpouring of love and appreciation he saw since February, he wrote, nothing touched him as deeply as that starry night sky.

In interviews and in his own writing, Sacks spoke often about his love for physical science and the periodic table. That love turned into a comfort in his last months of life when he began to feel his time running out.

"And now, at this juncture, when death is no longer an abstract concept, but a presence - an all-too-close, not-to-be-denied presence - I am again surrounding myself, as I did when I was a boy, with metals and minerals, little emblems of eternity," Sacks wrote.

He kept those little emblems on his writing desk, and they included a piece of thallium (element 81) given as a gift for his 81st birthday, and a piece of lead (element 82) for his just-celebrated 82nd birthday.

But the next element in the series revealed the true nature of Sacks' optimism, even as his cancer spread throughout his body.

"Bismuth is element 83," Sacks writes. "I do not think I will see my 83rd birthday, but I feel there is something hopeful, something encouraging, about having '83' around."

Even though he knew his death was looming, he chose not to wallow in it, but to reflect on and appreciate the life he had lived.

"I almost certainly will not see my polonium (84th) birthday, nor would I want any polonium around, with its intense, murderous radioactivity," Sacks writes. "But then, at the other end of my table - my periodic table - I have a beautifully machined piece of beryllium (element 4) to remind me of my childhood, and of how long ago my soon-to-end life began."