"The fundamental principle of science, the definition almost, is this: the sole test of the validity of any idea is experiment."

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I got a job at Metro and went in to see Louis Mayer, who told me he wanted me to be a producer. I said I wanted to write and direct. He said, "No, you have to produce first, you have to crawl before you can walk." Which is as good a definition of producing as I ever heard.

— Joseph L. Mankiewicz