Instantly a thick blackness seemed to enfold her and silence as of a dead world settled down upon her. Drowsy as she was she could not close her eyes nor refrain from listening. Darkness and silence were tangible things. She felt them. And they seemed suddenly potent with magic charm to still the tumult of her, to sooth and rest, to create thought she had never thought before. Rest was more than selfish indulgence. Loneliness was necessary to gain conciseness of the soul.
Zane Grey, The Call of the Canyon
darkness, loneliness