So watch your thoughts carefully. Make sure none of them are pointless or irrelevant. Most importantly, avoid thoughts that are nosy or mean-spirited. Train yourself to think only about things you could speak about openly. If someone suddenly asked what you were thinking, you should be able to answer honestly and boldly. Your thoughts should show that you are sincere and peaceful inside. This is how someone acts when they live for others, not just for pleasure or desire. Be free from fighting, envy, and suspicion. Be free from anything you would be ashamed to admit you were thinking about.
See therefore in the whole series and connection of thy thoughts, that thou be careful to prevent whatsoever is idle and impertinent: but especially, whatsoever is curious and malicious: and thou must use thyself to think only of such things, of which if a man upon a sudden should ask thee, what it is that thou art now thinking, thou mayest answer This, and That, freely and boldly, that so by thy thoughts it may presently appear that in all thee is sincere, and peaceable; as becometh one that is made for society, and regards not pleasures, nor gives way to any voluptuous imaginations at all: free from all contentiousness, envy, and suspicion, and from whatsoever else thou wouldest blush to confess thy thoughts were set upon.