Aesop's Fables date back to the 7th century BCE and may be the first known written expression of an often repeated proverb, namely: Necessity is the mother of invention. In the story called "The Crow and the Pitcher," during a terrible drought a thirsty crow finds water in a partially full water pitcher. But the mouth of the pitcher is too small to allow the crow to reach the water. The crow discerns that if it drops enough pebbles in the pitcher, this will raise the water level. So the crow proceeds with this plan and finally gets a drink. Aesop's…