One of the recurring themes in Marcus' handbook is leadership's responsibility to work intelligently with what it is given and not waste time fantasizing about a world of flawless people and perfect choices.

Look within. Within is the fountain of good, and it will ever bubble up, if thou wilt ever dig.

Never let the future disturb you. You will meet it, if you have to, with the same weapons of reason which today arm you against the present.

If any man can convince me and bring home to me that I do not think or act aright, gladly will I change; for I search after truth, by which man never yet was harmed. But he is harmed who abideth on still in his deception and ignorance.

If you separate from . . . everything you have done in the past, everything that disturbs you about the future . . . and apply yourself to living the life that you are living-that is to say, the present-you can live all the time that remains to you until your death in calm, benevolence, and serenity.

When you are offended at anyone's fault, turn to yourself and study your own failings. By attending to them, you will forget your anger and learn to live wisely.

To them that ask: Where hast thou seen the Gods, or how knowest thou certainly that there be Gods, that thou art so devout in their worship? I answer: Neither have I seen my own soul, and yet I respect and honor it.