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數學家是能在定理間找到類比的人；更好的數學家能在理論間看到類比；而最優秀的數學家能注意到類比之間的類比。

創新是將變化視為機會而非威脅的能力。

"A book is a dream that you hold in your hand."

The history of philosophy is not, like the history of the sciences, to be considered as a mere chronological record of discoveries and errors. It is the history of the human spirit in its endeavor to understand itself and its relation to the universe.