In the early 1600s, a young polymath, particularly adept at optics, put the finishing chisel to "A new contrivance of glasses, drawn from the most recondite speculations of perspective."

Facsimile of the telescope by Galileo with the main tube measuring 2 feet, 8 1/2 inches, and magnification of 21 times. Made by Cipriani and purchased from the Museo di Fisica e Storia Naturale, Florence, Italy, in 1923. Learn more.

This profound ocular embellishment - the telescope - allowed the very remarkable but also very fortuitous Galileo Galilei not only to see the imperfections of Earth's moon and the existence of the moons of Jupiter, but it also enabled him to refute, in his 1610 publication Sidereus Nuncius, all notions of the heavens as incorruptible spheres of the gods.

Of course, Sidereus Nuncius was published in Latin, an elite ecumenical language, and only widely available in the 18th century...

"Sidereus Nuncius Magna," by Galileo Galilei, bound together with "Dissertatis cum Sidereus Nuncio" by Johannes Kepler, published in 1611. Learn more.

But imagine what it must have been like to see scientific proof that the sky was not as it seemed and humanity was not the immovable point around which everything turned.

Imagine your entire visual-psychological world, formed piece by piece through a lens of your own experience; imagine that world completely undone. What positioning is necessary to survive and thrive?   Read more about finding our footing during life's upheavals in study of the constant state of change, an admiration of the beauty of breaking down, and the sequence of falling apart.

In contemplating Galileo's visual-psychological upheaval on humanity, I remembered neurologist Oliver Sacks (July 9, 1933 – August 30, 2015). This man entered the practice of medicine to understand his brother's schizophrenia and spent his career giving personhood to broken minds and whole, abundant souls.

 Oliver Sacks writing on a train.

In one of his many published cases, An Anthropologist on Mars, Sacks writes about a patient who lost his color vision instantaneously and how this patient coped with such a total upheaval of world and self-view.

Early in March 1986, I received the following letter:

'I am a rather successful artist just past 65 years of age. On January 2nd of this year, I was driving my car and was hit by a small truck on the passenger side of my vehicle. When visiting the emergency room of a local hospital, I was told I had a concussion. While taking an eye examination, it was discovered that I could not distinguish letters or colors. The letters appeared to be Greek letters. My vision was such that everything appeared to me as viewing a black and white television screen. Within days, I could distinguish letters and my vision became that of an eagle - I can see a worm wriggling a block away. The sharpness of focus is incredible. BUT - I AM ABSOLUTELY COLOR-BLIND. I have visited ophthalmologists who know nothing about this color-blind business. I have visited neurologists, to no avail. Under hypnosis I still can't distinguish colors. I have been involved in all kinds of tests. You name it. My brown dog is dark grey. Tomato juice is black. Color TV is a hodge-podge. ...'

Had I ever encountered such a problem before, the writer continued; could I explain what was happening to him - and could I help?

This seemed an extraordinary letter...

It was an extraordinary letter and an extraordinary case.

The patient, Mr. I., became color-blind (cerebral achromatopsia) in both sight and mental visualization. Sacks tells us, "Not only did he lose this distinguishing feature of seeing and association, but he was an artist; abstract canvases were now art without meaning. He knew but couldn't see... The world became disgusting, repulsive."

This situation strikes me as the opposite of John Keats' concept of "some shape of beauty," a visual thing that sets an absurd world right; for Mr. I., no such thing existed.

The sense of loss following his accident was overwhelming to Jonathan I., as it must be to anyone who loses colour, a sense that interweaves itself in all our visual experiences and is so central in our imagination and memory, our knowledge of the world, our culture and art. This sense of loss, in relation to the natural world, has been remarked upon in every case. ... This sense of loss and of shock was doubled and redoubled for Mr I., for he had not only lost the beauty of the natural world, and the world of people, and of the innumerable objects whose colours are part of daily life, but he had also lost the world of art, he felt - the world that, for fifty years or more, had absorbed his profoundly visual and chromatic talents and sensibilities. The first weeks of his achromatopsia were thus weeks of an almost suicidal depression.

Sacks' subsequent investigation and treatment of Mr. I. put him at the heart of neurological and psychological philosophy: how does the brain's physical composition and structure affect our abilities? Is there a "color center" in the brain? Does color pass through some mechanism in the brain and translate to sight? Or is it, according to Newton's principle of color theory, a wave that flows through individual cells? The visual perception of Mr. I, although greyscale, was profoundly rich in tonality and illumination. How did that affect his psychological self-view?

Colour is not a trivial subject but one that has compelled, for hundreds of years, a passionate curiosity in the greatest artists, philosophers, and natural scientists. The young Spinoza wrote his first treatise on the rainbow; the young Newton's most joyous discovery was the composition of white light; Goethe's great colour work, like Newton's, started with a prism; Schopenhauer, Young, Helmholtz, and Maxwell, in the last century, were all tantalized by the problem of colour; and Wittgenstein's last work was his Remarks on Colour. And yet most of us, most of the time, overlook its great mystery. Through such a case as Mr. I.'s, we can trace not only the underlying cerebral mechanisms or physiology but the phenomenology of colour and the depth of its resonance and meaning for the individual.

This case gave Sacks and the entire neurological/medical community a better understanding of how our brains process color and the psychological implications of color for the individual.   I'm very interested in the psychic nature of space, how various structures like walls or corners  orient our emotions and thus our concept of self. I also recommend Olivia Laing's The Lonely City, a significance study on artistic creations born of the cityscape.

Inspired by the sunrise, he started painting again – he started, indeed, with black-and-white painting that he called Nuclear Sunrise, and then went on to the abstracts he favoured, but now painting in black and white only. The fear of blindness continued to haunt him but, creatively transmuted, shaped the first 'real' paintings he did after his colour experiments. Black-and-white paintings he now found he could do, and do very well. He found his only solace working in the studio, and he worked fifteen, even eighteen, hours a day. This meant for him a kind of artistic survival: I felt if I couldn't go on painting,' he said later, ‘I wouldn't want to go on at all.'

Ultimately, Mr. I. saw himself and his abilities as privileged; he saw subtle textures and refined depth that color obscures. If our visual abilities and identity form our memory, imagination, etc., then we are also limited by those visualizations. Thus, Mr. I was no longer limited.

Indeed, it is an extraordinary case.

"Cystoseira foeniculacea" a species of British Algae taken in cyanotype impression by Anna Atkins. One of many specimens captured thus to become, in 1843, the first book with photographic illustrations. Yet the color of the algae is absurd, not natural. Learn more.

In his most personal memoir, On the Move, Oliver Sacks included a letter to his editor in which he confessed guilt about publishing his patients' cases.   September 19, 1972   
Dear Mr. Haycraft,   
I seem to be in one of those sky, dead depressed phases where one can only do nothing or blunder round in circles. The damn thing is that it needs only three days good work to finish the book, but I don’t know whether I am capable of this at the moment.   
I am in such an uneasy, guilt-stricken mood at the moment that I think I can’t bear the thought of any of my patients being recognizably exposed, or the hospital itself being recognized in Awakenings– maybe this is one of the things which is inhibiting me from finishing the book...

Sight, whether optical or internal, is central to our visualization of memory, inner landscape, and our definition of self. Read more from Gaston Bachelard, Richard Hugo, Annie Dillard, and Jorge Luis Borges on how we orient ourselves physically and mentally in a psychic space. And return to Sacks' last published collection of essays that sum up a life spent pursuing empathy.