The mark of a truly civilized man is confidence in the strength and security derived from the inquiring mind.
Curiosity is one of the permanent and certain characteristics of a vigorous mind.
I think, at a child's birth, if a mother could ask a fairy godmother to endow it with the most useful gift, that gift would be curiosity.
The most beautiful thing we can experience is the mysterious. It is the source of all true art and science.