133 lyric poems written over 17 years mourning the death of Arthur Henry Hallam, Tennyson's closest friend. In Memoriam is the Victorian age's great confrontation with religious doubt in the face of both personal grief and emerging evolutionary science; Darwin's ideas appear in it before Darwin published them. Its famous declaration ("'Tis better to have loved and lost / Than never to have loved at all") has become proverbial. Queen Victoria said it comforted her after Albert's death.

The case for it, the case against, and the rest of the canon open with Pro.