Reckoned physiologically, everything ugly weakens and afflicts man. It recalls decay, danger, impotence; he actually suffers a loss of energy in its presence. The effect of the ugly can be measured with a dynamometer. Whenever man feels in any way depressed, he senses the proximity of something ugly. His feeling of power, his will to power, his courage, his pride - they decline with the ugly, they increase with the beautiful.
Friedrich Nietzsche