“If consciousness is, as some inhuman thinker has said, nothing more than a flash of light between two eternities of darkness, then there is nothing more execrable than existence.”
The Tragic Sense of Life (1913), I : The Man of Flesh and Bone
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Miguel de Unamuno 199
19th-20th century Spanish writer and philosopher 1864–1936Related quotes
“It has been said that there is nothing more uncommon than common sense.”
Natural Theology (1836), Bk. II, Ch. III : On the Strength of the Evidences for a God in the Phenomena of Visible and External Nature, § 15; though provided without attribution of author, the saying "There is nothing more uncommon than common sense" has since become misattributed to particular people, including Frank Lloyd Wright.

“Nothing is more incontestable than the existence of our sensations; …”
in the Discours préliminaire de l’Encyclopédie http://fr.wikisource.org/wiki/Discours_pr%C3%A9liminaire_de_l%E2%80%99Encyclop%C3%A9die.
Context: Nothing is more incontestable than the existence of our sensations;...

Speak, Memory: A Memoir (1951)
Context: The cradle rocks above an abyss, and common sense tells us that our existence is but a brief crack of light between two eternities of darkness. Although the two are identical twins, man, as a rule, views the prenatal abyss with more calm than the one he is heading for (at some forty-five hundred heartbeats an hour).

“There is nothing more dangerous than to leap a chasm in two jumps.”
As quoted in Design for Power : The Struggle for the World (1941) by Frederick Lewis Schuman, p. 200; This is the earliest citation yet found for this or similar statements which have been attributed to David Lloyd George, as well as to Benjamin Disraeli, Winston Churchill, Vaclav Havel, Jeffrey Sachs, Rashi Fein, Walter Bagehot and Philip Noel-Baker. It has been described as a Greek, African, Chinese, Russian and American proverb, and as "an old Chassidic injunction". Variants:
Don't be afraid to take a big step if one is indicated. You can't cross a chasm in two small jumps.
The most dangerous thing in the world is to try to leap a chasm in two jumps.
Later life

Introductio ad prudentiam: Part II (1727), Gnomologia (1732)