Oliver Sacks always seemed propelled by joyful curiosity. The neurologist's writing is infused with this quality—equal parts buoyancy and diligence, the exuberant asking of difficult questions.

More specifically, Sacks had a fascination with ways of seeing and hearing and thinking. Which is another way of exploring experiences of living. He focused on modes of perception that are delightful not only because they are subjective, but precisely because they are very often faulty.

To say Sacks had a gift for this method of exploration is an understatement. He was a master at connecting curiosity to observation, and observation to emotion. Sacks died on Sunday after receiving a terminal cancer diagnosis earlier this year. He was 82.

Over the course of his life's work, Sacks approached his many questions with rigorous intellect and, above all, empathy. The best word for this, maybe, is grace. And it's everywhere in the elegant body of work he left behind—his many books, but also his shorter essays and interviews.

Here's a small sampling of some of Sacks's great conversations and shorter reflections.

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"Sabbath," The New York Times, 2015

Sacks reflects on what it means to live a good and worthwhile life — and what it took for him to achieve "a sense of peace within oneself."

Almost unconsciously, I became a storyteller at a time when medical narrative was almost extinct. This did not dissuade me, for I felt my roots lay in the great neurological case histories of the 19th century (and I was encouraged here by the great Russian neuropsychologist A. R. Luria). It was a lonely but deeply satisfying, almost monkish existence that I was to lead for many years.

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"Seeing God in the Third Millennium," The Atlantic, 2012

Sacks explores how the brain creates out-of-body experiences and religious epiphanies.

The tendency to spiritual feeling and religious belief lies deep in human nature and seems to have its own neurological basis, though it may be very strong in some people and less developed in others. For those who are religiously inclined, [a near-death experience] may seem to offer "proof of heaven," as Eben Alexander puts it.

Some religious people come to experience their proof of heaven by another route—the route of prayer, as the anthropologist T. M. Luhrmann has explored in her book When God Talks Back. The very essence of divinity, of God, is immaterial. God cannot be seen, felt, or heard in the ordinary way. Luhrmann wondered how, in the face of this lack of evidence, God becomes a real, intimate presence in the lives of so many evangelicals and other people of faith.

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Fresh Air interview, 1987

Oliver Sacks talks to NPR's Terry Gross about the relationship between the body and the mind—especially among patients whose ability to connect the two is altered.

The 'absolutely other' always seems uncanny and horrible and obscene and unholy and godforsaken. Words like this, or concepts like this, will be used by every patient,  irrespective of background of intelligence of education. The alienation is almost intrinsically in the area of subjectivity is sort of felt as anti-poetic, anti-religious. And by the same token, when it comes back, there's the feeling, to quote Dante, of the "holy  and glorious flesh." The body, in health, is always sort of felt as beautiful and holy, although one may not appreciate this until it is taken away.

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"Altered States," New Yorker, 2012

Sacks describes his experimentation with drugs, the resultant hallucinations, and how book-writing replaced his amphetamine habit.

I went back into the house and put on the kettle for another cup of tea, when my attention was caught by a spider on the kitchen wall. As I drew nearer to look at it, the spider called out, "Hello!" It did not seem at all strange to me that a spider should say hello (any more than it seemed strange to Alice when the White Rabbit spoke). I said, "Hello, yourself," and with this we started a conversation, mostly on rather technical matters of analytic philosophy. Perhaps this direction was suggested by the spider's opening comment: did I think that Bertrand Russell had exploded Frege's paradox? Or perhaps it was its voice—pointed, incisive, and just like Russell's voice, which I had heard on the radio. (Decades later, I mentioned the spider's Russellian tendencies to my friend Tom Eisner, an entomologist; he nodded sagely and said, "Yes, I know the species.")

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"This Year, Change Your Mind," The New York Times, 2010

Sacks explores the extent to which a person's brain can—and should—be "re-wired," especially in old age.

To what extent are we shaped by, and to what degree do we shape, our own brains? And can the brain's ability to change be harnessed to give us greater cognitive powers? The experiences of many people suggest that it can.

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"My Own Life," The New York Times, 2015

Sacks's essay about learning of his terminal cancer.

I cannot pretend I am without fear. But my predominant feeling is one of gratitude. I have loved and been loved; I have been given much and I have given something in return; I have read and traveled and thought and written. I have had an intercourse with the world, the special intercourse of writers and readers.

Above all, I have been a sentient being, a thinking animal, on this beautiful planet, and that in itself has been an enormous privilege and adventure.

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"My Periodic Table," The New York Times, 2015

Reflections on the years of life and their corresponding elements from the periodic table.

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 be seen only on 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 heavens' beauty, of eternity, was inseparably mixed for me with a sense of transience — and death.

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. At one end of my writing table, I have element 81 in a charming box, sent to me by element-friends in England: It says, "Happy Thallium Birthday,"a souvenir of my 81st birthday last July; then, a realm devoted to lead, element 82, for my just celebrated 82nd birthday earlier this month. Here, too, is a little lead casket, containing element 90, thorium, crystalline thorium, as beautiful as diamonds, and, of course, radioactive — hence the lead casket.

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"Strangers in the Mirror," Radiolab, 2010

A conversation between Sacks, the artist Chuck Close, and the Radiolab host Robert Krulwich about what it's like to live with Face Blindness—a condition that Sacks and Close both have.

Several times I have started apologizing to large, clumsy, bearded people and realize that it's a mirror. But it's even gone a stage further than that. Fairly recently, I was in a cafe in Chelsea Market with tables outside and while I was waiting for my food I was doing what people with beards often do: I started to preen myself and then I realized that my reflection was not doing the same thing. And that inside there was a man with a beard, possibly you, who wondered why I was sort of making faces at him.

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"Mishearings," The New  York Times, 2015

Sacks on finding delight in aberrations in hearing, and the strange concoctions that come from mishearing someone.

Every mishearing is a novel concoction. The hundredth mishearing is as fresh and as surprising as the first. … Mishearings are not hallucinations, but like hallucinations they utilize the usual pathways of perception and pose as reality — it does not occur to one to question them. But since all of our perceptions must be constructed by the brain, from often meager and ambiguous sensory data, the possibility of error or deception is always present. Indeed, it is a marvel that our perceptions are so often correct, given the rapidity, the near instantaneity, with which they are constructed.

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"Doctors Talk About Their Writing," The New York Times, 1986

Sacks describes how "The Case of George Dedlow," a short story about a Union army doctor published in The Atlantic in 1866, influenced his approach to writing.

So Silas Weir Mitchell, a young neurologist of rising reputation, opened "The Case of George Dedlow," which he published, with some hesitation, in The Atlantic Monthly in July 1866.

This case, mildly fictionalized but based on one personally known to him, was distinguished by a minuteness of clinical description, a degree of empathy, a brilliance of language and a boldness of imagination he had never dared show in his medical articles. It kindled the imagination of the public and the annoyance of his colleagues.

I cannot help identifying with Mitchell's predicament, his equivocal position between medicine and literature – though, unlike Mitchell, who wrote many novels later, I have no literary aspirations whatever, only the desire to report clinical reality in all its richness.

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Q&A with The Economist, 2010

I always wanted to get people's stories and access to their lives. I feel I'm at the interface of biography and biology, person and person-hood. I remember one man with Tourettes, who wrote and said that he had 'a tourettised soul', it affects one and one affects it—there's a liaison of a sort. A condition is sometimes a collusion, and sometimes a compromise.

Although it's up to me as a neurologist to diagnose the disease and to think in therapeutic terms, I always want to address the person as much as the disease, and I'm very glad my own doctor feels similarly. I'm not just a case to him, I'm a person responding to the situation. So I somehow sit between the biology and the humanist point of view.

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Q&A with Wired, 2009

Well, [my hallucinations] are rather dull by comparison. I don't see any images. I tend to see things like capital letters and numbers all jumbled up and moving rapidly. It's almost like a sort of Rosetta Stone. I can't actually read anything. All I see are isolated letters and sometimes strings of letters. These flicker and are faint and easily ignored…. They're black and white. I also see chessboards, which again are black and white…. Geometrical patterns go with activity [in] the primary visual cortex.

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TED talk, 2009

Sacks describes his research into blindness and geometrical hallucinations, and wonders whether cave art may have been derived from them.

We see with the eyes, but we see with the brain as well. And seeing with the brain is often called imagination. And we are familiar with the landscapes of our own imagination, our inscapes. We've lived with them all our lives. But there are also hallucinations as well, and hallucinations are completely different. They don't seem to be of our creation. They don't seem to be under our control. They seem to come from the outside, and to mimic perception.

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"The Joy of Old Age," The New York Times, 2013

At 80, Sacks reflects on what it's like to feel as though life is still just beginning.

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, too. One has seen grand theories rise, only to be toppled by stubborn facts. One is more conscious of transience and, perhaps, of beauty. At 80, 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, which I could not do when I was 40 or 60.