Certainty #51:

"The only certainty is that you must fail."
—Stephen Gresham, The Fraternity, 2004

Certainty #50:

"The only certainty is that climate will change again one day."
—Peter Haggett, Geography, 2001

Certainty #49:

"The only certainty is cruelty."
—Stephen Gresham, The Fraternity, 2004

Certainty #48:

"The only certainty we can possess is the aporia, the knowledge of the complete uncertainty, relativity, and provisionality of all knowledge."
—Patrick O'Neill, The Comedy of Entropy, 1990

Certainty #47:

"Rebellion gives the only possibility, the only probability, the only certainty."
—Queen's Quarterly, 1893

Certainty #46:

"The only certainty consists in exploratory laparotomy."
—John Blair Deaver, Surgery of the Upper Abdomen, 1908

Certainty #45:

"The only certainty, and the only thing that matters, is that the sun once existed in the sky."
—Bradley J. Stiles, Emerson's Contemporaries and Kerouac's Crowd, 2003

Certainty #44:

"You can't tell where you are, or why you're there, and the only certainty is overwhelming ambiguity."
—Neil Campbell, American Cultural Studies, 2004

Certainty #43:

"Faith is the only certainty because faith involves personal commitment."
—Lesslie Newbigin, A Reader, 2006

Certainty #42:

"The only certainty is that where there is violence, there is always and inevitably suffering."
—Andrew Gordon Fiala, Practical Pacifism, 2004

Certainty #41:

"The lonely certainty of failure."
—Elaine Feinstein, Badlands, 1986

Certainty #40:

"The only certainty is that our best guesses are utterly inadequate to the reality we strive to define."
—Horace J. Bridges, in his introduction to In Prase of Folly by Erasmus.

Certainty #39:

"The single certainty ... is that carbon is absorbed by growing trees."
—Anthony Smith, The Weather, 2000

Certainty #38:

"The single certainty is that, whatever the outcome, the need for sound, responsive, and responsible management will continue to grow."
—College and University Business Administration, 1974

Certainty #37:

"The only certainty in this issue is that, whatever he the outcome, it will please a few and greatly displease many others."
—Scott McCleskey, Achieving Market Integration, 2003

Certainty #36:

"The only certainty, the only truth, is the certainty of physical decay."
—Paul Cavill, The Christian Tradition in English Literature, 2007

Certainty #35:

"The single certainty seems to be that there will be no going back to the status quo ante."
—F.N. Norman, Constitutional Change in the United Kingdom, 2002

Certainty #34:

"Separation is the only certainty.  Transformation is the only constant."
—Joseph Cohen, Voices of Israel, 1990

Certainty #33:

"Guilt may be the one thing beyond doubt, the single certainty we have."
—David Lehman, The Perfect Murder, 2000

Certainty #32:

"The only certainty is: The lightness/weight opposition is the most mysterious, most ambiguous of all."
—Milan Kundera, The Unbearable Lightness of Being, 1984