Help us to complete the source, original and additional information
W.B. Yeats 255
Irish poet and playwright 1865–1939Related quotes

Earliest instance of this quote found on google books is the 1989 book Forest primeval: the natural history of an ancient forest by Chris Maser, but there it appears to be Maser's own thought (see p. 230 http://books.google.com/books?id=8EAHQM54E5gC&q=%a+mirror% followed by a different supposed Gandhi quote http://books.google.com/books?id=8EAHQM54E5gC&q=gandhi).
Disputed
Source: The Crying of Lot 49 (1966), Chapter 5

A 1915 letter written to his aunt in regards to his wife Molly Childers. Cited in " Erskine Childers " by Jim Ring, Faber and Faber, London , (1996), pg. 432.
Literary Years and War (1900-1918)

As quoted in Walden (1854) by Henry David Thoreau, Ch. 1
Attributed

Confucius, as quoted in Walden (1854) by Henry David Thoreau, Ch. 1
Misattributed