This book is also highly recommended by 800Muses

Loving What Is
Four questions that can change your life, by Byron Katie

From Amazon.com:

Remember the phrase "question authority"? Loving What Is is a workbook on questioning authority--but in this case, what is in question is the authority of our own fundamental beliefs about our relationships.

Known simply as "The Work," Byron Katie's methods are clean and straightforward. The basis is a series of four questions addressed to your own lists of written assumptions. Whether you're angry with your boss, frustrated with your teen's behavior, or appalled at the state of the world's environment, Katie suggests you write down your most honest thoughts on the matter, and then begin the examination. Starting with, "Is it true?" and continuing with explorations of "Who would you be without that thought?" this method allows you to get through unhelpful preconceptions and find peace. An integral part of the process is "turning the thought around," and at first this can seem like you're simply blaming yourself for everything. Push a little harder, and you'll find a very responsible acceptance of reality, beyond questions of fault and blame.

The book is filled with examples of folks applying The Work to a variety of life situations, and reading other's examples gets the idea across pretty clearly; chances are you'll find your own frustrations echoed on the pages a few times. Many chapters are divided into specific topics, such as couples, money, addictions, and self-judgments, with one chapter devoted to exploring the method with children.

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