[ecaradec]

I didn't see the purpose of it when I got told of the principle at school. The supposed control of error detection feel like a very vague benefit to me. Especially now with computers. Actually hashing of the chain of values would probably be more secure (like bitcoin yes).

However, I think the real value in double entry accounting is that it not only represent money you have but also things you own: If you buy a pen, you have less money, but you have an extra furniture pen and your accounting can reflect that. It can also reflect the loss of value of the pen over time.

It is also useful if you get in debt to buy something: you transfer money from a debt account to your current account, you buy the thing you wanted to buy and appropriatly report the value of what you own in accounting. You now have a thing, and a debt to be repaid in whatever term was agreed.

It's also very useful as a tool of control for state. All exchanges you have with other entities are recorded in a separate account. It's possible to take that account and check that the other entity accounting book match exchanges they have with you.