"The Western world is about to get ready to bury the biggest generation in history – the baby boomers," she said. "It only makes sense to start thinking about it. … Denying death can't be healthy."
Today, physician-assisted suicide is only openly legal in Switzerland, Belgium, the Netherlands and three U.S. states: Oregon, Washington and Montana.
Modern philosophy began with the suicide of Socrates, who was condemned to death. He tells his friend Phaedo, before drinking hemlock, "You should be prepared for death and not terrified by it," according to Critchley.
The Romans, as well as the Greeks, and the Vikings, had an open attitude toward suicide. The Vikings immolated themselves at sea in preparation for their heaven, Valhalla.
But in the fifth century, the view that suicide was a honorable gesture were rejected as paganism by Christians, who held that, "to kill yourself is to assume power only God has," said Critchley. "It's kind of a hubris."
The suicide note became popularized in the 18th century with the rise of literacy and newspapers in England, according to Crtichley.
By the Victorian age, in the 19th century, the culture revered death in elaborate memorials and funerals. "They had problems with sex," he said. "We talk endlessly about how much sex we are having and don't talk about death."
Critchley had an idea to do a School of Death -- the antithesis of the ever cheerful School of Life in London, which bills itself as "a cultural enterprise offering good ideas for everyday life" -- which led to his monthlong installation and workshops.
His book on Shakespeare's "Hamlet," who contemplates killing himself in the opening scene, was about to be published and so began Critchley's fascination with the final farewell.
Suicide notes are typically "obsessed with small details," he said. The Japanese Nobel-nominated author Yukio Mishima committed ritual suicide by Samurai sword after a failed coup d'etat in the 1970s.
"He was obsessed about whether the Japanese Army or Police had conducted certain activities," said Critchley.
Nazi leader Hermann Goering wrote three suicide notes after the Nuremburg trials. "When he finds out he is to be hanged and not shot, he said, 'I am happy to be shot, but to be hanged is too great a shame.'"
Suicide notes are often an attempt to blame someone else or send "hate messages to the world."
"I have taken my life to provide capital for you," Alex C. wrote to his wife after battling the IRS for taking all his money. "It's the only decision I can make. ... I hope you understand I love you completely."
Some are copycats. Take, for example, those who throw themselves off the iconic Golden Gate Bridge. "They jump off the side facing the city, not the ocean," Critchley said. "This idea of suicide as a kind of exhibitionism on display is important."
He said that he feared people would think the class was a joke, but he added that students, who had to write their own suicide notes, were, "earnest and engaged."
Wrote one woman: "I am so filled with love it is still all too much to bear. I cannot find my way. The world is all wrong and although I withstood the worst of it, I lost out."
But another was less emotional: "I am sorry, mostly to my dog. Love, Lauren. P.S. Please don't bury me in Los Angeles."
In the end, Critchley's favorite note to emerge from his class was the humorous one written by his wife, Jamieson, a psychiatrist:
Break a leg, or all your legs. I better break fast.
With all my love-hate,
Jamieson (who is about to drive us off a cliff)