With the unknown, one is confronted with danger, discomfort, and care; the first instinct is to abolish these painful states. First principle: any explanation is better than none. . . . The causal instinct is thus conditional upon, and excited by, the feeling of fear. The "why?" shall, if at all possible, not give the cause for its own sake so much as for a particular kind of cause -- a cause that is comforting, liberating, and relieving.