C.S. Lewis, in "Letters To Children."
In writing, don’t use adjectives which merely tell us how you want us to feel about the thing you’re describing. I mean, instead of telling us a thing was terrible, describe it so that we’ll feel terrified. Don’t say it was delightful; make us say ‘delightful’ when we’ve read your description. You see, all these words ‘horrifying’, ‘wonderful’, ‘hideous’, ‘exquisite’, are only like saying to your readers, “please, would you do my job for me?”