“Kant's position is extremely subtle — so subtle, indeed, that no commentator seems to agree with any other as to what it is.”

Alternative translation: Subtle and insubstantial, the expert leaves no trace; divinely mysterious, he is inaudible. Thus he is master of his enemy's fate.
Alternative translation: O divine art of subtlety and secrecy! Through you we learn to be invisible, through you inaudible and hence we can hold the enemy's fate in our hands.
The Art of War, Chapter VI · Weaknesses and Strengths
Context: Be extremely subtle, even to the point of formlessness. Be extremely mysterious, even to the point of soundlessness. Thereby you can be the director of the opponent's fate.

(zh-TW) 微乎微乎，至於無形；神乎神乎，至於無聲；故能為敵之司命。
Alternative translation: Subtle and insubstantial, the expert leaves no trace; divinely mysterious, he is inaudible. Thus he is master of his enemy's fate.
Alternative translation: O divine art of subtlety and secrecy! Through you we learn to be invisible, through you inaudible and hence we can hold the enemy's fate in our hands.
The Art of War, Chapter VI · Weaknesses and Strengths

God Is An Iron (1977)
Context: Man has historically devoted much more subtle and ingenious thought to inflicting cruelty than to giving others pleasure — which, given his gregarious nature, would seem a much more survival-oriented behavior. Poll any hundred people at random and you'll find at least twenty or thirty who know all there is to know about psychological torture and psychic castration — and maybe two who know how to give a terrific back-rub.

Source: Presocratic Philosophy: A Very Short Introduction (2004), Ch. 1 : Lost words, forgotten worlds

Source: The Cambridge Encyclopedia of the English Language, 1987, p. 60

"The Limits of Control"
The Adding Machine: Collected Essays (1985)

Source: Smashed: Story of a Drunken Girlhood

Conversations with Carl Sagan (2006) http://books.google.ca/books?id=gJ1rDj2nR3EC&pg=PA70&redir_esc=y#v=onepage&q&f=false, edited by Tom Head, p. 70
Context: Those who raise questions about the God hypothesis and the soul hypothesis are by no means all atheists. An atheist is someone who is certain that God does not exist, someone who has compelling evidence against the existence of God. I know of no such compelling evidence. Because God can be relegated to remote times and places and to ultimate causes, we would have to know a great deal more about the universe than we do to be sure that no such God exists. To be certain of the existence of God and to be certain of the nonexistence of God seem to me to be the confident extremes in a subject so riddled with doubt and uncertainty as to inspire very little confidence indeed.

The Abolition of Work (1985)