“Life was a pleasure; he looked back at its moments, many of them as much shrouded in mist as the opposite bank of the Thames; objectively, many of them held only misery, fear, confusion; but afterwards, and even at the time, he had known an exhilaration stronger than the misery, fear, or confusion. A fragment of belief came to him from another epoch: 'Cogito ergo sum'. For him that had not been true; his truth had been, 'Senito ergo sum'. I feel so I exist. He enjoyed this fearful, miserable, confused life, and not only because it made more sense than non-life.”

“Cogito ergo sum, certamen ergo sum.”

“Dubito, ergo cogito, ergo sum.(English: "I doubt, therefore I think, therefore I am")”

“Cogito ergo sum. (I think, therefore I am.)”

“I am not much for philosophy, but that old Descartes, he got me thinking. And therefore being. Anyone? Anyone? Cogito ergo sum jokes? No? Okay.”

“An anxiety with no object or purpose in the present, and in the future nothing but endless sacrifice, by means of which he would attain nothing - that was what his days on earth held in store for him... What good was life to him? What prospects did he have? What did he have to strive for? Was he to live merely in order to exist? But a thousand times before he had been ready to give up his existence for an idea, for a hope, even for an imagining. Existence on its own had never been enough for him; he had always wanted more than that. Perhaps it was merely the strength of his own desires that made him believe he was a person to whom more was allowed than others.”