From Planet of the Blind: (click for full article)
No one knows when the forerunner of today’s guide dogs first appeared. Drawings of blind people accompanied by dogs date back to the 17th century. Those early pairings were most likely memorization teams, one pictures the dog leading its partner through the village square. It’s clear no substantial training was involved. But we can imagine the tremendous bond with dogs that developed between the uncharted and lonely blind people of prior ages. It is a safe bet that dogs solved the puzzle of solitude for blind travelers who lived in a time when sightlessness was a great calamity. (The idea that blind men and women could be taught to read was a late development in cultural history, as Diderot’s essay Lettre sur les aveugles published in 1749 offered the first speculation that raised letters might be possible.) The world of the blind has been a dismal place throughout much of history. It’s possible to say, along with the poet Pablo Neruda that pure faith cannot withstand the assaults of winter, but your survival is more likely with a dog. Sometimes when I think about the ancient blind with their lives of begging and fiddle playing, their relentless wandering, homelessness, sickness, I weep to imagine the righteous loyalty of those early dogs.