No man should talk worse than he writes, no man should write better than he should talk… The oral sentence is clearest because it is the product of millions of daily efforts to be clear and strong. It represents the work of the race for thousands of years in perfecting an effective instrument of communication. 
The Best Writing is Simple, and the simplest communication we have is conversational speech. Therefore, to most effectively transmit ideas, we should write in a way that closely resembles how we talk.
L. A. (Lucius A. Sherman, Analytics of literature, a manual for the objective study of English prose and poetry. Boston, Ginn, 1893. ↩︎