The author of 22 books, of which 3 continue to make his name.

He was born in an immensely wealthy family in Copenhagen in 1813, the youngest of 7 children.

Death was around him constantly from a young age, and was to obsess him throughout his career.

It is, in a sense, his only theme.

Not only was he extremely physically frail,

by the time he was 22, all his siblings had died except for he and a brother.

It drove him to furious production of books over 15 years.

On a single day in 1843 he published no less than 3 works.

He wasn't writing for the money; he was working to save himself, and, he thought, humanity.

As it happened, he made it to the age of 42, then died of an excruciating spinal disease.

In "Either/Or" and "Fear and Trembling", what Kierkegaard wants to do above all

is wake up and give up our cozy sentimental illusions.

He systematically attacks the pillars of modern life: our faith in family, our trust in work, our attachment to love,

and our general sense that life has purpose and meaning.

His enemies were the smug in all their guises,

particularly, the prosperous Danish haute bourgeoisie, and the members of the established Danish church.

He tells us, "As I grew up I opened my eyes and saw the real world, and I began to laugh and I haven't stopped since.

I saw that the meaning of life was to get a livelihood,

that the goal of life was to be a High Court judge,

that the brightest joy of love was to marry a well-off girl,

that wisdom was what the majority said it was,

that passion was to give a speech,

that courage was to risk being fined ten dollars,

that cordiality was to say "you're welcome" after a meal,

and that the fear of God was to go to communion once a year.

That's what I saw and I laughed."

Kierkegaard was especially caustic about the 19th century understanding of love,

and the new ideology of passionate marriage, which aimed to unite desire with prudence,

and suggested that one could enjoy all the thrills of a love affair,

and, at the same time, all the stability for long-term relationship.

But, Kierkegaard mocked the notion that one could ever fuse romantic laugh with marriage,

that one could have passion and sex, and, at the same time, children, stability, and routine.

He respected both, he just couldn't believe you could have them both at the same time-

in a cozy marriage sanctified by the state and the neighborhoods.

His belief arose out of his own tortured love life.

He fell in love with a beautiful, precocious, and talented 18-year-old girl, called Regine Olsen,

only then to break off the engagement as he realized

that to try and live with her forever would also mean killing the love that had drawn him to her.

Everywhere he turned, Kierkegaard saw intolerable incompatibilities, and impossible choices.

It led him to one memorable explosion in "Either/Or":

"Marry and you will regret it. Don't marry; you will also regret it."

"Marry or don't marry; you will regret it either way."

"Laugh at the world's foolishness; you will regret it."

"Weep over it; you'll regret that too."

"Hang yourself; you'll regret it. Don't hang yourself and you'll regret that too."

"Whether you hang yourself or don't hang yourself, you will regret both."

"This, gentlemen, is the essence of all philosophy."

The mention of laughter is not a coincidence; key to Kierkegaard's philosophy is that:

the only intelligent tactical response to life's horror is to laugh defiantly at it.

Rarely has a philosopher taken humor as seriously.

Kierkegaard is often described as the founder of the philosophical movement known as "existentialism",

because, in him, we find all the themes that would so interest later thinkers, like Sartre, Camus, and Heidegger.

The book that fascinated the existentialists was Kierkegaard's, "The Concept of Anxiety", published in 1844,

in which he emphasized a new word, "angest", or "angst", as we know it in English,

a condition where we understand how many choices we face,

and how little understanding we can ever have of how to exercise these choices wisely.

As Kierkegaard wrote, "Life can only be understood backwards, but must be lived forwards".

Our constant angst means that unhappiness is more or less written into the script of life,

as he wrote, "anyone who has given the matter any serious thought will know that I'm right when I say,"

"it's not possible for anyone to be absolutely, and in every conceivable way, completely content,"

"not even for a single half hour of his life."

"No one has come into the world without crying. No one asks when you want to enter the world; no one asks when you want to leave."

"How empty and meaningless life is; we bury a person, throw three shovels of earth over him,"

"drive out in a coach, drive back in a coach, and console ourselves that we still have life enough left to live."

"But really, how long is three score and ten; why not just get it over with straight away?"

For Kierkegaard there was, however, one answer that he put forward ever more stridently in his later works: Jesus Christ.

Kierkegaard loathed the Christianity of the established Danish church,

but he adored the simple truths of the Gospels that his father taught him as a boy

For him, Christianity was a religion of extreme surrender to a theology of almost peasantlike simplicity:

one was to be ready to die for Christ, to give up all attachment to worldly things, and to love all humans like one's siblings.

Kierkegaard wasn't interested in justifying his attachment to Christianity through rational means;

instead, he recommended a dramatic and now famous 'leap of faith',

wherein one wouldn't apply one's puny mind to attempting to prove the existence of God,

one would merely switch off one's faulty rational faculties, and jump into the idea of God as the total solution.

As he put it, "To have faith is to lose your mind and to win God".

Like Marxist communism, Kierkegaard's solutions to the problems of being human

are far less convincing and interesting than the diagnoses of our ills; few of us now make that leap,

but Kierkegaard deserves our attention for the beautifully bitter, caustic look he casts on the human condition.

He's one of the few philosophers one can turn to when the world has badly let us down, and we're in need of a friend

who can fully understand the dark places we're in once the sentimental illusions, that normally keep us going, fall away.