Robin Williams, an Oscar-winning actor whose career spanned almost 40 years, passed away on Monday, but his legacy lives on.

He was a father-turned-nanny in Mrs. Doubtfire, a professor Sean Maguire in Good Will Hunting, a doctor in Patch Adams as well as Teddy Roosevelt in the comedy Night at the Museum. Williams' list of credits includes many more unforgettable roles that have made him one of the greatest actor's of our time.

Below are some of his most memorable on-screen quotes.

John Keating in Dead Poets Society in 1989: "Carpe. Hear it? Carpe. Carpe diem. Seize the day, boys. Make your lives extraordinary."

"No matter what anybody tells you, words and ideas can change the world."

Peter Banning in Hook in 1991: "To live would be an awfully big adventure."

Parry in The Fisher King in 1991: "Gentlemen, haven't we learned anything from the music of John Lennon? All we need is love."

The voice of Genie in Aladdin in 1992: "To be my own master. Such a thing would be greater than all the magic and all the treasures in all the world."

The title character in Mrs. Doubtfire in 1993: "If there's love, dear... those are the ties that bind, and you'll have a family in your heart, forever. All my love to you, poppet. You're going to be all right. Bye bye."

The title character in Jack in 1996: "Please, don't worry so much. Because in the end, none of us have very long on this Earth. Life is fleeting. And if you're ever distressed, cast your eyes to the summer sky when the stars are strung across the velvety night. And when a shooting star streaks through the blackness, turning night into day, make a wish, and think of me. Make your life spectacular."

Sean Maguire in Good Will Hunting in 1997: "You don't know about real loss because it only occurs when you've loved something more than you love yourself. I doubt you've ever dared to love anybody that much."

"You're not perfect, sport, and let me save you the suspense: this girl you've met, she's not perfect either. But the question is whether or not you're perfect for each other."

Chris Nielsen in What Dreams May Come in 1998: "You have to break in half to love somebody."

The title character in Patch Adams in 1998: "Our job is improving the quality of life, not just delaying death."

"You treat a disease, you win, you lose. You treat a person, I guarantee you, you'll win, no matter what the outcome."

Rainbow Randolph in Death To Smoochy in 2002: "Friends come in all sizes, take it from me! Golly gee, size doesn't matter, when you want some friendly patter from a pal who is true."

Lance in World's Best Dad in 2009: "I used to think the worst thing in life was to end up all alone. It's not. The worst thing in life is ending up with people who make you feel all alone."

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