"The three-toed sloth lives a peaceful, vegetarian life in perfect harmony with its environment. "A good-natured smile is forever on its lips," reported Tirler (1966). I have seen that smile with my own eyes. I am not one given to projecting human traits and emotions onto animals, but many a time during that month in Brazil, looking up at sloths in repose, I felt I was in the presence of upside-down yogis deep in meditation or hermits deep in prayer, wise beings whose intense imaginative lives were beyond the reach of my scientific probing. Sometimes"