“Adults are only obsolete children.”

“Every once in a while, I get mad. 'The Lorax' came out of my being angry. The ecology books I'd read were dull... In 'The Lorax,' I was out to attack what I think are evil things and let the chips fall where they might.”

“Once-ler! You're making such smogulous smoke - my poor swomee swans, why they can't sing a note! No one can sing who has smog in his throat.”

“You ought to be thankful a hole heaping lot, for The places and people you're lucky you're not!”

“Plant a new Truffula. Treat it with care. Give it clean water. And feed it fresh air.”

“Adult males are what their moms designed them.”

“Cannot we let [children] be themselves, and enjoy life in their own way? You are trying to make another you. One's enough.”

“What art can paint or gild any object in after life with the glow which nature gives to the first baubles of childhood? St. Peter's cannot have the magical power over us that the red and gold covers of our first picture-book possessed.”