Robert Louis Stevenson 
Essays in the Art of Writing [PDF ebook] 

A writer learns this early, and it is his chief support; he goes on unafraid, laying down the law; and he is sure at heart that most of what he says is demonstrably false, and much of a mingled strain, and some hurtful, and very little good for service; but he is sure besides that when his words fall into the hands of any genuine reader, they will be weighed and winnowed, and only that which suits will be assimilated; and when they fall into the hands of one who cannot intelligently read, they come there quite silent and inarticulate, falling upon deaf ears, and his secret is kept as if he had not written.