Glaucon, the "owl-eyed" one, is said to be him "who can see in the gathering twilight." His naming may suggest a kind of Platonic banter, because Glaucon certainly has difficulty in perceiving parts of Socrates' argument, particularly the analogies. For example, when Socrates in Book II is trying to elucidate the character of the ideal Guardian, he says that a well-bred dog has the qualities of a philosopher, and Glaucon admits that he is confused. Then Socrates explains that a family dog and a philosopher share a common trait, and that common trait is knowledge: The dog knows an acquaintance and does not attack, but the dog does not know a stranger and attacks. Glaucon says that he has never thought about that trait in a dog, which bespeaks a curious ignorance of dogs generally and a potential danger for a budding thinker.