“Enthusiasm does not always speak for those who arouse it, but always for those who experience it.”

First attributed to Thoreau in A year of sunshine: cheerful extracts for every day in the year‎ (Kate Sanborn, 1886) and American literature‎ (Mildred Cabell Watkins, 1894), but there is no known citation to Thoreau's works.
Misattributed

Have You a Hobby?, Answers, 21 April 1934

Reproduced in The Collected Essays of Sir Winston Churchill, Vol IV, Churchill at Large, Centenary Edition (1976), Library of Imperial History, p. 288. ISBN 0903988453
The 1930s

A Short History of Decay (1949)

"La Paquet Rouge" in Opéra (1925)

Source: Animal Liberation

"I Speak Eternally" http://www.avatarmeherbaba.org/erics/ispeak.html in Love Alone Prevails (1981) by Kitty Davy, p. 166, 179.
General sources
Context: External silence helps to achieve inner Silence, and only in internal Silence is Baba found — in profound inner Silence. I am never silent. I speak eternally. The voice that is heard deep within the soul is My voice — the voice of inspiration, of intuition, of guidance. Through those who are receptive to this voice, I speak.

Acceptance Speech http://www.washingtonpost.com/wp-srv/politics/daily/may98/goldwaterspeech.htm as the Republican Presidential candidate, San Francisco (July 1964)
Unsourced variant: Now those who seek absolute power, even though they seek it to do what they regard as good, are simply demanding the right to enforce their own version of heaven on earth, and let me remind you they are the very ones who always create the most hellish tyranny.
Context: Those who seek absolute power, even though they seek it to do what they regard as good, are simply demanding the right to enforce their own version of heaven on earth. And let me remind you, they are the very ones who always create the most hellish tyrannies. Absolute power does corrupt, and those who seek it must be suspect and must be opposed. Their mistaken course stems from false notions of equality, ladies and gentlemen. Equality, rightly understood, as our founding fathers understood it, leads to liberty and to the emancipation of creative differences. Wrongly understood, as it has been so tragically in our time, it leads first to conformity and then to despotism.