When nineteenth-century scientists began ranking animals by
intellect, they were perplexed by the dog. Chimpanzees and other
primates were physically most like humans, exhibiting "human
behaviors": problem solving, tool making, and the like. But,
unlike the dog, chimps were useless. (And nineteenth-century men
had a broader experience of useful animals than we do today.) In
Mental Evolution in Animals (1883) zoologist George Romanes
ranked dogs and apes equally, below only humankind. Other
theorists made capital of a blurry meaning. "Ah yes," they said,
"The ape is more intelligent, but the dog is more sagacious."
This stroke pleased abstract thinkers and practical livestock
men alike. The root of sagacity is "a keen attention to the
senses, particularly the sense of smell," but, of course, the
word has come to mean rather more than that. The Border Collie
has been called "the wisest dog in the world." The shepherd's
dog, described in Dr. Caius's British Dogges (1570) sounds very
like the Border Collie of tod