Search men's governing principles, and consider the wise, what they shun and what they cleave to.

Nothing proceeds from nothingness, as also nothing passes away into non-existence.

Enter others' minds and let them enter yours.

A person's life is what their thoughts make it.

I am an old man and have had many worries, but most have never come to pass.

Retire into thyself. The rational principle which rules has this nature, that it is content with itself when it does what is just, and so secures tranquility.

For nowhere either with more quiet or more freedom from trouble does a man retire than into his own soul, particularly when he has within him such thoughts that by looking into them he is immediately in perfect tranquility; and I affirm that tranquility is nothing else than the good ordering of the mind.