A superstition is a premature explanation that overstays its time.

Whoever ceases to be a student has never been a student.

We despair of changing the habits of men, still we would alter institutions, the habits of millions of men.

Man can live about forty days without food, about three days without water, about eight minutes without air, but only for one second without hope

Whoever ceases to be a student has never been a student.

Doubt is the beginning, not the end, of wisdom.