For almost 60 years William Shatner has boldly gone in so many directions it’s mind boggling.

He’s an actor, writer, producer, singer and international celebrity.

Tell Shatner he’s the human version of the Energizer Bunny and he concedes “there are definitely days when I look in the mirror and see a red bar on my forehead that reads ‘low battery.’ ”

It’s one of the few times during his phone call Shatner displays his trademark self-deprecating levity.

The man who played Captain James T. Kirk for three decades is embarking on a serious mission.

On Thursday, Shatner, 73, will take part in Once Upon a Chair, the Canadian Intensive Care Foundation of Calgary’s fundraiser at the Jubilee Auditorium.

Shatner admits he is besieged by charities and has to choose carefully as his time is at a premium.

“I think we should all do everything we can to aid the doctors and nurses who work in intensive-care units. I understand the money being raised at the Calgary auction will go toward educating future doctors and nurses.

“These professionals perform such an incredible life-saving service.”

For this fundraiser, the CICF commissioned 10 chairs to become canvases for local artists. They were to alter them as much as possible to encourage fierce bidding at the auction.

Five of the chairs will be up for bids.

Four others are being given to patients who survived against tremendous odds due to the care they received in a Calgary intensive-care unit.

The 10th chair will be presented to the family of a patient who succumbed to the illness despite the efforts of the intensive-care personnel.

“I’ll be on stage with one of the chairs reading a fairy tale the CICF has sent me,” says Shatner, adding he’s learned “my chair can talk back but I think I can handle it if it becomes a heckler.”

He is quick to point out his roots are in live theatre, having started as a young actor with the Stratford Shakespeare Festival.

“I love the immediate connection of an audience, whether it’s a packed theatre or just an actor, I’m playing opposite,” says Shatner, as he left the set of Boston Legal, calling from his limo.

The series in which he plays the eccentric law firm partner Denny Crane has garnered him a Golden Globe and an Emmy.

“I did two scenes for Boston Legal today and feel invigorated because it’s what I love doing most.”

Shatner insists his preparation for his continuing role in Boston Legal, films such as Miss Congeniality or a charity appearances is essentially the same.

“It’s all about solving problems, and the bigger the problem the more I relish the challenge.”

He’s adamant his Star Trek persona was never as big a career problem as his harshest critics once claimed.

“Kirk was an important part of my career. It wasn’t a problem. It was a gift.

“But I’ve done much more than one role. Much more.”

He also points out, he often beats his critics to the punch.

“I’ve always been able to laugh at myself. That’s not just important, but essential in this profession.

“You can’t take yourself too seriously.”

He says he feels blessed to have had such a long, fulfilling career.

“It’s been joyful. I feel joyful. We pass through one life. If you don’t have fun and if you don’t make it joyful for yourself, you’re the big loser.”

Tickets for the CICF fundraiser and gala are available through Ticketmaster.