Donald Rumsfeld worked for three presidents, led the Pentagon twice and, whether you agree with him or not, he has been one of the most controversial figures in recent American history. The debut of his new book, " Rumsfeld's Rules: Leadership Lessons in Business, Politics, War and Life," gives him an opportunity to share the rules by which he has lived his life. Don't confuse those with the words that have come out of his mouth; "I stand by what I meant," he says.

Rumsfeld, 80, sat down with ABC News' Jonathan Karl to talk about the book. Watch the interview here, and see below for a list of some of his most famous - and infamous - quotations that he professes in his new book.

Rumsfeldism: "Reports that say that something hasn't happened are always interesting to me, because there are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know."

At a February 2002 news briefing, then-Secretary of Defense Rumsfeld said the words for which he is now most famous. Embroiled in the decision to invade Iraq, Rumsfeld was asked by a reporter about his knowledge of a direct link between Baghdad and weapons of mass destruction. Many decried his above response as unnecessarily convoluted, while others defended him, including renowned linguist Geoffrey Pullum, who described the quotation as "impeccable, syntactically, semantically, logically, and rhetorically." The title of Rumsfeld's 2011 memoir, "Known and Unknown," comes from the quote.

Rumsfeld Rule: "If you are working from your inbox, you are working on other people's priorities."

Excerpt from Rumsfeld's book: "With emails and phone calls coming in over the transom every hour of the day, it's easy to get lost in inbox items, forgetting what your main objectives are or spending too little time on them. The task of a leader is to have an organization work out of his or her outbox. In every management position I held, I generated dozens of queries and requests to the staff each day, so that our team was working on our agreed priorities. In the Pentagon, these memos became known as "snowflakes" because the white pieces of paper fell with abandon on various offices in the building. To this day, I still send out dozens of memos and letters each week. I also keep a "tickle" file of my notes to remind me when I should hear back from the addressees or if I need to remind them to get back to me - gently, of course."

Rumsfeldism: "Stuff happens … and it's untidy, and freedom's untidy, and free people are free to make mistakes and commit crimes and do bad things."

In an April 2003 news conference, Rumsfeld responded to a question about widespread looting throughout Iraq. The United States had invaded Iraq and a reporter wanted to know what was going to be done to restore law and order. Responding later, he believed that the quote left the media with an unfortunate impression, writing in his book, "It left an inaccurate and regrettable impression that stuck with me for some time."

Rumsfeld Rule: "The cover-up is always worse than the event."

Calling it in his book "Rule One" of "the two most important rules in Washington, D.C.," this quote speaks largely to his experience in government during the Nixon years, but also applies to modern political scandals. Referring directly to the Benghazi scandal plaguing the Obama administration, Rumsfeld told Fox News in an interview , "I don't know how you can call it anything else."

Rumsfeldism: "I'm not into this detail stuff. I'm more concept-y."

In a January 2002 interview with the Washington Post, Rumsfeld's off-the-cuff remark is often taken out of context and applied in a derogatory way by critics of the Bush Administration during the Iraq War. Really, Rumsfeld was commenting on notes he had made in preparation for the interview.

Rumsfeld Rule: "Arguments of convenience lack integrity and inevitably trip you up."

In his book, he described the answer to such arguments: "What I do in such circumstances is to rephrase the question so it is based on a premise that I consider more accurate or germane." It seems he lives by his own rules. In an interview, ABC News' Jonathan Karl said to Rumsfeld, "You always would question the premise of a question." His response: "Only when the premise was fallacious."

Rumsfeldism: "I can't think of anything funnier than a handful of congressmen walking around [Iraq.] They'd have to be there for the next 50 years trying to find something. It's a joke."

This quote refers to an August 2002 invitation by Iraq to members of Congress to tour suspected biological, chemical and nuclear weapons sites in Iraq. Rumsfeld suggested the lawmakers alone would have a hard time finding anything. The quote gained weight through the years when no such weapons were found.

Rumsfeldism: "You and a few other critics are the only people I've heard use the phrase 'immediate threat.' I didn't, the president didn't. And it's become kind of folklore that that's what's happened."

This infamous March 2002 quote came from an interview on CBS News' "Face the Nation." Known for undermining the premise of journalists' questions, Rumsfeld found himself in an awkward situation when it was pointed out that he did, indeed, say in September 2002, "But no terrorist state poses a greater or more immediate threat to the security of our people and the stability of the world than the regime of Saddam Hussein in Iraq."

Rumsfeldism: "Certainty without power can be interesting, even amusing. Certainty with power can be dangerous."

In his memoir, "Known and Unknown," Rumsfeld writes this statement about Richard Nixon's White House aide John Ehrlichman.