Ferdinando Scianna he has spent over thirty years undertaking the task of photographing sleeping people, a theme that he only became aware of while sifting through his archive in search of a lost negative:

“I have always had a penchant for photographing people asleep, but it was many years before I realized that this had unwittingly grown into something more like an obsession; and even then the discovery only came to me by chance. I had lost a negative (a common occurrence for an untidy photographer), and in my search for it was forced to embark on one of those dreaded journeys through the files of contact prints in my archive.
If reality is, as I believe, the mirror of the photographer and not the other way round, to run through tens of thousands of images produced by the camera over so many years is like experiencing a trial run of the hypothetical film imagined by Vitaliano Brancati: one image of one man’s face each day, from birth to death, to be viewed eventually as a speeded-up projection of a life. But in this case the life is your own.
From a journey like this, as from every journey into memory, one returns with many anguished feelings, and sometimes with new discoveries. On this particular occasion I realized just how many of my pictures were of sleeping people; and that I had always been taking such pictures ever since I started photography, wherever the chances of life and my job had led me. I decided to set aside the most decent ones, and ended up with several hundreds. A second, more critical scrutiny did away with most of them, and I was left with about thirty. These became the nucleus around which, after seven or eight years of second thoughts, substitutions and new photographs, a first exhibition laboriously took shape at the Turin Biennale in 1987. I say laboriously, not because I find taking photographs tiring – on the contrary, it is fun, serious sensual fun, and I’d say light work – but because something odd, though understandable, had happened. Having become aware of my obsessive tendency to photograph sleeping people, I began to ounce lice a photographic bird of prey on anybody, man or animal, who dared to shut his eyes even for an instant to steal a nap.”
- Ferdinando Scianna

The images of To sleep, perchance to dream are interspersed with an anthology of quotations about sleep and dreaming (by William Shakespeare, Dant, Victor Hugo and many others).