Søren Kierkegaard on Philosophical pessimism

“Listen to the cry of a woman in labor at the hour of giving birth — look at the dying man’s struggle at his last extremity, and then tell me whether something that begins and ends thus could be intended for enjoyment.”

“The whole order of things fills me with a sense of anguish, from the gnat to the mysteries of incarnation; all is entirely unintelligible to me, and particularly my own person. Great is my sorrow, without limits. None knows of it, except God in Heaven, and He cannot have pity.”

“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 will regret that too; laugh at the world's foolishness or weep over it, you will regret both. Believe a woman, you will regret it; believe her not, you will also regret it [...] Hang yourself, you will regret it; do not hang yourself, and you will regret that too; hang yourself or don't hang yourself, you'll regret it either way; whether you hang yourself or do not hang yourself, you will regret both. This, gentlemen, is the essence of all philosophy.”

“I stick my finger in existence — it smells of nothing. Where am I? Who am I? How came I here? What is this thing called the world? What does this world mean? Who is it that has lured me into the world? Why was I not consulted, why not made acquainted with its manners and customs instead of throwing me into the ranks, as if I had been bought by a kidnapper, a dealer in souls? How did I obtain an interest in this big enterprise they call reality? Why should I have an interest in it? Is it not a voluntary concern? And if I am to be compelled to take part in it, where is the director? I should like to make a remark to him. Is there no director? Whither shall I turn with my complaint?”