- Dr. John Dolittle: Albert Einstein, he came in with that wild hair and everybody thought he was crazy. And Muhammad Ali, he came out saying what rounds he was going to beat people in, going "I'm the greatest!", everybody thought he was crazy. And Joan of Arc, she heard voices.
- Maya Dolittle: Like you, daddy?
Eddie Murphy - Dr. John Dolittle
Kyla Pratt - Maya Dolittle

“- Darlene: Are you aware that you're yelling?
- Eddie: My voice is raised in emphasis. It's a perfectly legitimate use of volume.”
Robin Wright - Darlene
Sean Penn - Eddie

“The voice you hear is not my speaking voice - but my mind's voice. I have not spoken since I was six-years-old. No one knows why - not even me. My father says it is a dark talent, and the day I take it into my head to stop breathing will be my last.”

Holly Hunter - Ada

“She has spoken to me. I heard her voice. There was no sound, but I heard it here. Her voice was there in my head. I watched her lips, they did not make the words, yet the harder I listened the clearer I heard her, as clear as I hear you, as clear as I hear my own voice.”

Sam Neill - Stewart

“I hear the voices in my head.”
Béatrice Dalle - Betty