All theory is against the freedom of the will: all experience for it.
Dr. Samuel Johnson, quoted by Boswell, Life of Johnson, Wednesday, 5 April 1778

All philosophy can do is to destroy idols. And that means not creating a new one -
for instance as in the "absence of an idol."
Ldwig Wittgenstein, "The Big Typesript" in Hans-Johann Glock, A Wittgenstein Dictionary. London: Blackwell Publishers, Ltd. 1999

The critique of religion is the prerequisite of every critique.
Karl Marx, A Contribution to the Critique of Hegel's "Philosophy of Right," p. 131