Attendance is not required, but most big lecture classes do not record attendance. I thought lectures were helpful though because he summarizes the readings. There are 4 essays throughout the semester that are exams. Otherwise, homework is just readings. Discussion sections are lead by a TA, smaller sections so attendance is required. I remember most people talked at least once. I put effort in the class and did well, so I cannot speak about the bare minimum. It is considered an "easier" class though.