We have had terrible experience of the psychic power which can produce effects such as the possession by devils of a whole people. But we have less experience of the psychic powers which console and strengthen and fill our minds with peace, which encourage the despairing and drive out hatred and envy and the will to hurt others. Although, thank God, most of us have known someone with this psychic power, though perhaps it seemed to us to have only a small field of activity - a family, a circle of friends, at the best a people. But perhaps we are wrong; perhaps the power which proceeds from good men and women is too subtle for us with our limited abilities to understand. Perhaps its waves are like the light-waves and sound-waves of which our eyes and ears only perceive a small part.
-Sigrid Undset, Catherine of Siena