Try to remember this: what you project
Is what you will perceive; what you perceive
With any passion, be it love or terror,
May take on whims and powers of its own.
Therefore a numb and grudging circumspection
Will serve you best — unless you overdo it,
Watching your step too narrowly, refusing
To specify a world, shrinking your purview
To a tight vision of your inching shoes,
Which may, as soon as you come to think, be crossing
An unseen gorge upon a rotten trestle.

"Walking to Sleep" (1969)