I was listening to NPR yesterday and heard the following story about the father of accounting. Since one of my dearest friends is an accountant, this is dedicated to him.
Every transaction gets entered twice in financial records. If one day you sold three gold coins' worth of pepper, you would write that the amount of cash you had went up by three gold coins. You would also write in that the amount of pepper you had went down by three gold coins' worth."You could itemize the profits in each account, so you knew which products you were doing well in and which you weren't. Then you could start to think about how you would change your business activities. It was just a whole revolution in the way of thinking about business and trade."
Double Entry: How the Merchants of Venice Created Modern Finance