It isn't the first step that concerns me, but both sides escalating to the fourth or fifth stepöand we don't go to the sixth because there is no one around to do so.

-Kennedy, Robert F(rancis)
On the possibility of initiating nuclear warfare. Thirteen Days (published1969).

The sense of wonder that is the sixth sense. And it is the natural religious sense.

-Lawrence, D(avid) H(erbert)
'Hymns in a Man's Life'. Collected in Pheonix II: Uncollected, Unpublished and Other ProseWorks (1968).