“The absence of the will to live is, alas, not sufficient to make one want to die.”

Source: Among the Hidden

Lyrics, The Eraser (2006)

The Tragic Sense of Life (1913), III : The Hunger of Immortality
Context: Glorious is the risk! — καλος γαρ ο κινδυνος, glorious is the risk that we are able to run of our souls never dying … Faced with this risk, I am presented with arguments designed to eliminate it, arguments demonstrating the absurdity of the belief in the immortality of the soul; but these arguments fail to make any impression on me, for they are reasons and nothing more than reasons, and it is not with reasons that the heart is appeased. I do not want to die — no; I neither want to die nor do I want to want to die; I want to live for ever and ever and ever. I want this "I" to live — this poor "I" that I am and that I feel myself to be here and now, and therefore the problem of the duration of my soul, of my own soul, tortures me.

Absence conquers Love.

Source: Veronika Decides to Die

Cited by a character in J. D. Salinger's The Catcher in the Rye (1951) as a statement of Stekel, this has often been attributed to Salinger, and may actually be a paraphrase by him of a statement of the German writer Otto Ludwig (1813-1865) which Stekel himself quotes in his writings:
Das Höchste, wozu er sich erheben konnte, war, für etwas rühmlich zu sterben; jetzt erhebt er sich zu dem Größern, für etwas ruhmlos zu leben.
The highest he could raise himself to was to die gloriously for something; now he rises to something greater: to live humbly for something.
Gedanken Otto Ludwigs : Aus seinem Nachlaß ausgewählt und herausgegeben von Cordelia Ludwig (1903) p. 10 http://archive.org/stream/gedankenottolud00ludwgoog#page/n39/mode/2up; this is quoted by Stekel in "Die Ausgänge der psychoanalytischen Kuren" in Zentralblatt für Psychoanalyse : Medizinische Monatsschrift für Seelenkunde (1913), p. 188 http://archive.org/stream/ZB_III_1913_4_5_k#page/n19/mode/2up, and in Das liebe Ich : Grundriss einer neuen Diätetik der Seele (1913), page 38 http://books.google.de/books?id=PgFAAAAAIAAJ&q=r%C3%BChmlich.
Misattributed

Quoted by Salinger as a statement of the psychoanalyst Wilhelm Stekel in The Catcher in the Rye, this has often been attributed to Salinger, and it may actually be a paraphrase by him of a statement of the German writer Otto Ludwig (1813-1865) which Stekel himself quotes in his writings:
Das Höchste, wozu er sich erheben konnte, war, für etwas rühmlich zu sterben; jetzt erhebt er sich zu dem Größern, für etwas ruhmlos zu leben.
The highest he could raise himself to was to die gloriously for something; now he rises to something greater: to live humbly for something.
Gedanken Otto Ludwigs : Aus seinem Nachlaß ausgewählt und herausgegeben von Cordelia Ludwig (1903), p. 10 http://archive.org/stream/gedankenottolud00ludwgoog#page/n39/mode/2up; this is quoted by Stekel in "Die Ausgänge der psychoanalytischen Kuren" in Zentralblatt für Psychoanalyse : Medizinische Monatsschrift für Seelenkunde (1913), p. 188 http://archive.org/stream/ZB_III_1913_4_5_k#page/n19/mode/2up, and in Das liebe Ich : Grundriss einer neuen Diätetik der Seele (1913), page 38 http://books.google.de/books?id=PgFAAAAAIAAJ&q=r%C3%BChmlich.
Disputed

Source: Madame Bovary

"Nothingness" [Hư vô], as quoted in "Shattered Identities and Contested Images: Reflections of Poetry and History in 20th-Century Vietnam" by Neil Jamieson, in Crossroads: An Interdisciplinary Journal of Southeast Asian Studies, Vol. 7, No. 2, 1992, p. 87, and in Understanding Vietnam by Neil Jamieson (University of California Press, 1995), p. 162