“There can be knowledge of the diabolical, but no belief in it, for more of the diabolical than there is does not exist.”

Congressional speech (1849)
Context: I affirm, in words as true and literal as any that belong to geometry, that the man who withholds knowledge from a child not only works diabolical miracles for the destruction of good, but for the creation of evil also. He who shuts out truth, by the same act opens the door to all the error that supplies its place. Ignorance breeds monsters to fill up all the vacuities of the soul that are unoccupied by the verities of knowledge. He who dethrones the idea of law, bids chaos welcome in its stead. Superstition is the mathematical complement of religious truth; and just so much less as the life of a human being is reclaimed to good, just so much more is it delivered over to evil. The man or the institution, therefore, that withholds knowledge from a child, or from a race of children, exercises the awful power of changing the world in which they are to live, just as much as though he should annihilate all that is most lovely and grand in this planet of ours, or transport the victim of his cruelty to some dark and frigid zone of the universe, where the sweets of knowledge are unknown, and the terrors of ignorance hold their undisputed and remorseless reign.

Nobel Prize Lecture (1993)
Context: Tongue-suicide is not only the choice of children. It is common among the infantile heads of state and power merchants whose evacuated language leaves them with no access to what is left of their human instincts for they speak only to those who obey, or in order to force obedience. The systematic looting of language can be recognized by the tendency of its users to forgo its nuanced, complex, mid-wifery properties for menace and subjugation. Oppressive language does more than represent violence; it is violence; does more than represent the limits of knowledge; it limits knowledge. Whether it is obscuring state language or the faux-language of mindless media; whether it is the proud but calcified language of the academy or the commodity driven language of science; whether it is the malign language of law-without-ethics, or language designed for the estrangement of minorities, hiding its racist plunder in its literary cheek — it must be rejected, altered and exposed. It is the language that drinks blood, laps vulnerabilities, tucks its fascist boots under crinolines of respectability and patriotism as it moves relentlessly toward the bottom line and the bottomed-out mind. Sexist language, racist language, theistic language — all are typical of the policing languages of mastery, and cannot, do not permit new knowledge or encourage the mutual exchange of ideas.

"What is Philosophy?(Part 2)" http://www.xenosystems.net/what-is-philosophy-part-2a/ (2013)

Introductio ad prudentiam: Part II (1727), Gnomologia (1732)

Source: 1980s–1990s, Knowledge and Decisions (1980; 1996), Ch. 1 : The Role of Knowledge

Source: The Dance of Life http://www.gutenberg.net.au/ebooks03/0300671.txt (1923), Ch. 5