“Sorrow is knowledge, those that know the most must mourn the deepest, the tree of knowledge is not the tree of life.”

IV. Defense and Support : Building blocks for the O.T.O. Temple
Parsifal and the Secret of the Graal Unveiled (1914)
Context: Closing Word
Learn to eat of the tree of Knowledge, and of the tree of Life enjoy the fruit. Seek both within yourself, and so you recognize them and know their place, you are come to the highest rung of the 12 step ladder.
Through this will the Divine-Love be awoken that does not have a place in the twisted minds of men, but dwells in his heart, from which the salvational current will be born which gives us the vision of the eternal light and annihilates all falsity.
"The eternal-feminine draws us up?!"

The Heaven of Animals (l. 29–34).
The Whole Motion; Collected Poems, 1945-1992 (1992)

Emperor and Galilean (1873), as quoted by Lester B. Pearson in his address on accepting the Nobel Peace Peace Prize in Oslo, Norway (10 December 1957) http://nobelprize.org/nobel_prizes/peace/laureates/1957/pearson-acceptance.html

83, a slight variant of this was later published in Parables and Paradoxes (1946):
We are sinful not merely because we have eaten of the Tree of Knowledge, but also because we have not yet eaten of the Tree of Life. The state in which we find ourselves is sinful, quite independent of guilt.
Also quoted in this form in The Parables of Peanuts (1968) by Robert L. Short, and Like a Dream, Like a Fantasy: The Zen Teachings and Translations of Nyogen (2005)
The Zürau Aphorisms (1917 - 1918)
Context: We are sinful not only because we have eaten of the Tree of Knowledge, but also because we have not yet eaten of the Tree of Life. The state in which we are is sinful, irrespective of guilt.

Act III, sc. i.
The Rivals (1775)

The Progress of Fifty Years (1893)
Context: Get but a truth once uttered, and 'tis like
A star new born that drops into its place;
And which, once circling in its placid round,
Not all the tumult of the earth can shake.
Henceforth the leaves of the tree of knowledge were for women, and for the healing of the nations.

Though often attributed to Garvey, this statement first appears in Charles Siefert's 1938 pamphlet, The Negro's or Ethiopian's Contribution to Art.
Misattributed

"The Idea of Progress" http://books.google.com/books?id=TbgYAAAAYAAJ&q=%22The+fruit+of+the+tree+of+knowledge+always+drives+man+from+some+paradise+or+other%22&pg=PA5#v=onepage, Romanes Lecture (27 May 1920), reprinted in Outspoken Essays: Second Series (1922)

[Raman, C. V., Chandralekha, Why the Sky is Blue: Dr. C.V. Raman Talks about Science, http://books.google.com/books?id=LOC3vbnTgHYC&pg=PT1, 2010, Tulika Books, 978-81-8146-846-8, 17]