Character in sickness and health

I lied when I said, "It's not me, not the real me. It's the sickness that's speaking." For sickness has no voice, and it was me, a nasty me. How can I claim that my goodness, my lofty feelings, constitute the "real me," and that my rancor and malice are just "sickness" and not me?

We can readily see in others what we do not care, or dare, to see in ourselves. The patients I work with are chronically ill. They have, they know they have, little or no hope of recovery. Some of them show a transcendent humor and gallantry, an unspoilt love and affirmation of life. But others are bitter, virulent, envenomed—great haters, great spiters, murderous, demonic. It is not the sickness but the person that shows here, his collapse or corruption with the cruelties of life. If we have youth, beauty, blessed gifts, strength, if we find fame, fortune, favor, fulfillment, it is easy to be nice, to turn a warm heart to the world. But let us be disfavored, disfigured, incapicitated, injured; let us fall from health and strength, from fortune and favor; let us find ourselves ill, miserable and without clear hope of recovery—then our mettle, our moral character, will be tried to the limit. 

Oliver Sacks, A Leg to Stand on (1984 with 1993 afterward), p. 148 [Funny: the Kindle edition doesn't indicate the publisher.]