“There is no happiness without knowledge. But knowledge of happiness is unhappy; for knowing ourselves happy is knowing ourselves passing through happiness, and having to, immediatly at once, leave it behind. To know is to kill, in happiness as in everything. Not to know, though, is not to exist.”
Ibid., p. 328
The Book of Disquiet
Original: Não há felicidade senão com conhecimento. Mas o conhecimento da felicidade é infeliz; porque conhecer-se feliz é conhecer-se passando pela felicidade, e tendo, logo já, que deixá-la atrás. Saber é matar, na felicidade como em tudo. Não saber, porém, é não existir.
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Fernando Pessoa 288
Portuguese poet, writer, literary critic, translator, publi… 1888–1935Related quotes

Variant: If what Proust says is true, that happiness is the absence of fever, then I will never know happiness. For I am possessed by a fever for knowledge, experience, and creation.

“To sense the peace of extinguished passion, happiness in not knowing the ultimate knowledge.”
"The Over-Sky Sign," p. 5
The Sign and Its Children (2000)

Statement made to a correspondent in Paris in 1976 — reported in John Callcott, United Press International (December 21, 1982) "Arthur Rubinstein, At Age 95; Concert Pianist and Bon Vivant, Boston Globe.
Attributed

“It is a kind of happiness to know how unhappy we must be.”
C’est une espèce de bonheur, de connaître jusqu’à quel point on doit être malheureux.
Maxim 8 of the Maximes supprimées.
Later Additions to the Maxims

“Man is unhappy because he doesn't know he's happy. It's only that.”
Part II, Ch. I
The Possessed (1872)
“Happiness is the best revenge, you know? Just be happy. It's a choice.”
Source: Heart of the Matter