This is a rush transcript from "The O'Reilly Factor," May 14, 2008. This copy may not be in its final form and may be updated.

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BILL O'REILLY, HOST: "Back of the Book" segment tonight, a new book by actor William Shatner called "Up Till Now," the autobiography. The work is causing some controversy, because it seems not everything was heavenly in the world of "Star Trek."

Mr. Shatner joins us now.

Video: Watch the interview

I'm reading over your book. And most actors aren't as candid as you are. They go, "Oh, everybody loved everybody on the set." And it was all fun. And behind the scenes, they were stabbing, stabbing, stabbing.

But a show like "Star Trek," so enormous, elevated you into stardom, obviously. You were an actor before, a star afterwards. People change on the set, don't they?

WILLIAM SHATNER, ACTOR: They do. And it is — there is rivalry. But there's not much an actor can do about getting a role. The agents can parlay and make things happen or producers get the favorites in. But the actor themselves, very difficult to do something about anything other than trying to perform.

O'REILLY: But millions of people watching "Star Trek," and they still watch it. It's a phenomenon. And Roddenberry creates it, and you get hired. And Nimoy gets hired. And everybody looks at the show as, No. 1, a very professional presentation, very enjoyable, but they don't think behind the scenes. And then you write that there was some tension between you and Nimoy.

SHATNER: There was, to begin with. Publicity. Probably jealousy on my part.

O'REILLY: Your part?

SHATNER: He got a lot of publicity as Spock. And I — if I remember correctly, I thought maybe I should get some of it.

O'REILLY: But you were the leading man. You were the big guy.

SHATNER: I was a young actor and — and intent on my territory.

O'REILLY: You were jealous of him?

SHATNER: Yes.

O'REILLY: Were you mean to him?

SHATNER: I don't think so. And in the end, what I'm trying to put into perspective is this feud, Leonard and I didn't have much of a feud to begin with. And now we're bosom friends; we're brothers.

But what happened as I — as the show went on and I began to do interviews, books that I was writing, one of the actors said to me six or seven years after the show was over, would you like to hear how we despised you? And that came as a shock. What are you talking about?

And Nichelle began to describe how much they disliked me because — and then I never really got a good reason. And it's 40 years later.

O'REILLY: Did that hurt your feelings?

SHATNER: Yes. I was astounded.

O'REILLY: When they said, "Look, we really didn't like you back then, but they didn't wouldn't say anything, because you were the big guy and we could get in trouble. So...

SHATNER: Something like that.

O'REILLY: But that's really — that's not unusual in show business or television business. I mean, when big guys make it, and the other guys don't make it, he's a rotten guy. You know how it is. Human nature.

SHATNER: In New York, I'm on a Broadway show, big hit Broadway show, and an actor is clapping me on the shoulder when he gets a laugh. And it's a nice gentle hit when he gets a laugh. When his laugh doesn't hit, and he mistimed it...

O'REILLY: Hit you a little harder, huh?

SHATNER: So one day I said, "You've got to stop." He said no. And I went to everybody. It took weeks. I went up the ladder.

And finally, I said if you hit me like that, I'm going to hit you back. So he hit me. So I hauled off and punched him.

O'REILLY: What play was that?

SHATNER: "The World of Suzy Wong." And he hit...

O'REILLY: There wasn't any violence in "Suzy Wong," as I remember.

SHATNER: Well, no.

O'REILLY: So it was hard to fake that?

SHATNER: It was hard to fake it. What was that? I don't know.

O'REILLY: Was he in a brawl? What happened here?

SHATNER: I hit this actor back.

O'REILLY: Good for you. I would have done it much earlier.

SHATNER: As we know.

O'REILLY: As we know, absolutely. "Boston Legal." You have big time Candace Bergen, Spader, serious actors. Do this, that and the other thing. Here again there must be some rivalry and tension on the set, because you're all artists.

SHATNER: But you know we're not. It's astonishing. These are professional, mature.

O'REILLY: Ah, mature. Actors. How do you get that? You have to...

SHATNER: You've got to work on yourself.

O'REILLY: I do.

SHATNER: But then you lose your charm.

O'REILLY: That's what I say, you know.

SHATNER: This book — this book is a panoply of my life. The incidents we're talking about are part of the book.

O'REILLY: And the overall message of the book is?

SHATNER: Is decisions you make at all times should be done consciously, because they reverberate the rest of your life.

O'REILLY: Yes, don't get drunk out of your mind and do some crazy things.

SHATNER: Well, those are big. What about moving the paper, saying hello to somebody. Anything. Just be aware of your life.

O'REILLY: That's good. That's a good message. Because the unintended consequences of slights and everything else come back to bite you.

SHATNER: There you go. Let alone the big ones of you should have gone left when you should have gone right.

O'REILLY: Right, absolutely. And the choice of companions.

All right. I'm going to finish up. I didn't have time to read the whole thing. The book is "Up Till Now."

Thanks for coming in here. We appreciate it.

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