[Lush]

I always found Denethor's situation particularly chilling.

The book hints at the notion that he was originally faced with the death of his wife and was not able to overcome it, leading to his despair to snowball into the disaster that eventually found him looking into the palantir, slowly deteriorating, losing Boromir after sending him on the road to ostensibly rescue Gondor, and ending up about to burn his remaining family member to death.

I think there is some sort of connection there; the idea, perhaps, that if one is not able to deal with losing a loved one, one may eventually lose everything and everyone they've ever loved as the resullt. It is a very cruel irony that Denethor who, after Findulias' death, "became more grim and silent than before, and would sit long alone in his tower deep in thought, forseeing that the assault of Mordor would come in his time" would end up trying to torch Faramir, who was all that remained of his family.