It is said that a common farm labourer uses 500 words, and educated business man 3,000, the average novelist 5,000 and great scholars and public men 7,000. "Shakespeare" in his poems and plays uses 21,000, the largest vocabulary ever possessed by any member of the human race.
With the exception of "Shakespeare's" Francis Bacon's vocabulary was the greatest ever known, and Dr. Samuel Johnson, the great lexicographer, said that
"a Dictionary of the English language might be compiled from Bacon's works alone."
Is it a coincidence that "Shakespeare's" vocabulary, which is the largest ever attained by any man in any language at any time, is equalled only by Francis Bacon's in its extent and richness?
SirBacon.org - Sir Francis Bacon's New Advancement of Learning