Beware of silent dogs and still waters. – Proverb

Every human being has, like Socrates, an attendant spirit; and wise are they who obey its signals. If it does not always tell us what to do, it always cautions us what not to do. – Lydia Maria Child

If one has to jump a stream and knows how wide it is, he will not jump. If he does not know how wide it is, he will jump, and six times out of ten he will make it. – Proverb