— Arthur Schopenhauer, Essays and Aphorisms
Einstein paraphrasing Schopenhauer. Reportedly from On The Freedom Of The Will (1839), as translated in The Philosophy of American History: The Historical Field Theory (1945) by Morris Zucker, p. 531 <!-- plus many other published works -->
Man can do what he wants but he cannot want what he wants.
As quoted in The Motivated Brain: A Neurophysiological Analysis of Human Behavior (1991) by Pavel Vasilʹevich Simonov, p. 198
We can do what we wish, but we can only wish what we must.
As quoted by Einstein in "What Life Means to Einstein: An Interview by George Sylvester Viereck" The Saturday Evening Post (26 October 1929) p. 17. A scan of the article is available online here http://www.saturdayeveningpost.com/wp-content/uploads/satevepost/what_life_means_to_einstein.pdf (see p. 114).
Man can control what he wills, but not how he wills.
Man can indeed do what he wants, but he cannot control what it is that he wants. -->