“The greatest of empires, is the empire over one’s self.” —Publilius Syrus

I love quoting from my favorite works, and I have a giant trove of quotations.

Because I collect so many quotations, for me, one of the most difficult, and more pleasant, tasks of writing a book  is choosing the epigraph. I spend an inordinate amount of time pondering my favorite candidates. The epigraph must both be a beautiful passage to read in isolation, yet also cast unexpected light on the argument of the book. It’s so hard to choose!

Today’s quotation is what I chose, after much inner debate, to be the epigraph for Better Than Before. It’s  an assertion that I believe with all my heart, and is at the core of the argument of the book, and expressed in haunting language. “The greatest of empires, is the empire over one’s self.”

My argument about habits is:

There’s no magic, one-size-fits-all solution. @gretchenrubin (Click to Tweet!)

It would be great if we could all “Do it first thing in the morning!” “Start small!” “Have a weekly cheat day!” or “Do it for thirty days!” and form a habit, and sometimes those strategies do work — but sometimes they don’t. Why not? What can we do instead, if they don’t work?

We all must understand ourselves, and given what’s true for us, pick the strategies that are right for us — and in this way, become the master of ourselves.

I considered adding a second epigraph to Better Than Before, but many of the people who helped me edit the book thought that this line struck an ominous note. To me, it’s not negative, just the truth. But true, it’s a harsh truth: John Gardner’s observation, “Every time you break the law you pay, and every time you obey the law you pay.”

It’s a line with many, many meanings. In the context of habit-formation, I think about it whenever I ponder the Four Tendencies. Because, whether you’re an Upholder like me, or a Rebel, or a Questioner or an Obliger, there’s no evading it: with your habits, every time you break the law you pay, and every time you obey the law you pay.

In the end, I decided to leave it out, because I thought the more important quotation, from Publilius Syrus, would be more powerful if it stood alone.

For a while, I also intended to include a quotation by William James (of course; you can’t talk about habits without quoting William James) but in the end decided to leave that single line to stand alone.

If you had to pick an epigraph for your life, or a saying that summed up your personal philosophy, what would you choose? Many people now put a quotation in the footer of their emails, and I always enjoy seeing what they choose — or what they clip and post on the fridge, or needlepoint onto a pillow, or frame and hang on the wall.

Gretchen Rubin is the author of the #1 New York Times Bestseller The Happiness Project—an account of the year she spent test-driving the wisdom of the ages, current scientific studies, and lessons from popular culture about how to be happier—and the recently released Happier at Home and Better Than BeforeOn her popular blog, The Happiness Project, she reports on her daily adventures in the pursuit of happiness. For more doses of happiness and other happenings, follow Gretchen on Facebook and Twitter.

Image courtesy of Jordan McQueen.