“Engineers can compute but not define,

mathematicians can define but not compute,

economists can neither define nor compute.”

Nassim Taleb

The Bed of Procrustes: Philosophical and Practical Aphorisms

Nassim Taleb is a writer and thinker.  He grew up in Lebanon and grew rich in the USA.  He is the author of among other books, The Black Swan.  He recently created the concept of the Antifragile and wrote a book about it.  His writing is highly recommended for open minded people.