Musk is known by its perfume and not by what the druggist says. A scholar is silent like the perfumer’s casket but displays accomplishments, whilst an ignoramus is loud-voiced and intrinsically empty like a war-drum.
A learned man among blockheads
(So says the parable of our friends)
Is like a sweetheart among the blind
Or a Qaroon (Korah) among unbelievers.
Saadi Shirazi
http://www.poemhunter.com/poem/ch-08-on-rules-for-conduct-in-life-maxim-37/