How Can You Tell if an. Animal is Intelligent?
E. W. Menzel Jr. State University of New Yorkat Stony Brook
"Darwin revolutionized our study of nature by taking the actual variation among actual things as central to the reality, not as an annoying disturbance to be wished away. That revolution is not yet completed. Biology remains in many ways obdurately Platonic. . . . (For example,) Neurobiologists want to know how the brain works, but they don't say whose brain. Presumably when you've seen one brain you have seen them all" ( Lewontin, 1983).
Trying to arrive at an airtight definition of intelligence is as thankless a job as trying to define Life or Man. The worst pitfall here, so far as most biologists are concerned, is Platonic essentialism ( Mayr, 1982). Let me give two brief illustrations. According to Diogenes Laertius:
Plato had defined Man as an animal, biped and featherless, and was applauded. Diogenes plucked a fowl and brought it into the lecture-room with the words, 'Here is Plato's man.' In consequence of which there was added to the definition, 'having broad nails.' ( 1970, p. 43).
As Plato was conversing about Ideas and using the nouns 'tablehood' and 'cuphood,' (Diogenes) said, 'Table and cup I see; but your tablehood and cuphood, Plato, I can nowise see.''That's readily accounted for,' said Plato, 'for you have the eyes to see the visible table and cup; but not the understanding by which ideal tablehood and cuphood are discerned.' ( 1970, p. 55).
Are the ghosts of Plato and Diogenes dead? I do not think so, at least when I read the current debates about vultures that in some sense are "tool users," rats