It may be asked why anyone would bother to sit in a lecture which was the literal
repetition of an available text.
Such a question would betray an oversimpliﬁed view of what goes on in a classroom.
• What one really learns in class is what one does not know at the time one is learning.
• The person lecturing to us was logic incarnate. His pauses, hesitations, emphases, his
betrayals of emotion (however rare), and sundry other nonverbal phenomena taught us
a lot more logic than any written text could.
• We learned to think in unison with him as he spoke, as if following the demonstration
of a calisthenics instructor.
• [The] course permanently improved the rigor of our reasoning.
(From a reminiscence by Gian-Carlo Rota)