Illness is the night-side of life, a more onerous citizenship. Everyone who is born holds dual citizenship, in the kingdom of the well and in the kingdom of the sick. Although we all prefer to use only the good passport, sooner or later each of us is obliged, at least for a spell, to identify ourselves as citizens of that other place.

Illness As Metaphor (1978), foreword, p. 3, Farrar, Straus and Giroux ISBN 0-374-52073-9