Fear is the main source of superstition， and one of the main sources of cruelty. To conquer fear is the beginning of wisdom， in the pursuit of truth as in the endeavour after a worthy manner of life.

In mathematics, the simplest questions often lead to the deepest insights.

艺术是沉思。它是心灵的愉悦，心灵在自然中探寻，并在那里预见到自然本身所激发的精神。

快乐激发玩耍的冲动，兴趣激发探索的冲动，满足激发品味和整合的冲动，而爱在安全、亲密的关系中激发这些冲动的循环往复。