If I were asked what is the greatest single lesson that a child can be taught, my reply would be, "The Lesson of the Porcupine." For a great philosopher has taught us that human social life can be compared with a group of porcupines sleeping on the ground on a wintry night. Should they roll together to gain warmth, they are apt to hurt one another with their prickly quills. Should they then toll apart to avoid pain, their loss of mutual support renders them isolated and exposed to the chill night. Porcupine comfort and contentment, then, are to be found in their discovery of the Perfect Distance.
We may define Perfect Distance as a state of separation that achieves warmth without intrusion, and independence without isolation. Transposing this to human experience we may conceive of the comfortable person as one who is warmly independent - when they comes near they neither nettles nor smothers; when they withdraw they neither neglects nor desert. Their love is without barbs; their self-sufficiency is compassionate and without estrangement.