When the future novelist David Foster Wallace was about 14 years old, he asked his father, the University of Illinois philosophy professor James D. Wallace, to explain to him what philosophy is, so that when people would ask him exactly what it was that his father did, he could give them an answer. James had the two of them read Plato's Phaedo dialogue together, an experience that turned out to be pivotal in his understanding of his son. "I had never had an undergraduate student who caught on so quickly or who responded with such maturity and sophistication," James recalls. "This was this first time I realized what a phenomenal mind David had."