When a learner, in the fullness of his powers, comes to great truths unstaled by premature familiarity, he rejoices in the lateness of his lessons.

Dumbness and silence are two different things.

To render aid to the worthless is sheer waste. Rain does not freshen the Dead Sea, but only enables it to dissolve more salt.

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

A calculating engine is one of the most intricate forms of mechanism, a telegraph key one of the simplest. But compare their value.

Form may be of more account than substance. A lens of ice will focus a solar beam to a blaze.

Is any knowledge worthless? Try to think of an example.