Accountants will talk of ``credits'' and ``debits'', but the meaning
is often different from the layman's understanding.  To avoid
confusion, Ledger uses only subtractions and additions, although the
underlying intent is the same as standard accounting principles.

Recall that every posting will involve two or more accounts.
Money is transferred from one or more accounts to one or more other
accounts.  To record the posting, an amount is @emph{subtracted}
from the source accounts, and @emph{added} to the target accounts.

In order to write a Ledger transaction correctly, you must determine where
the money comes from and where it goes to.  For example, when you are
paid a salary, you must add money to your bank account and also
subtract it from an income account:

@smallexample
9/29  My Employer
    Assets:Checking                           $500.00
    Income:Salary                            $-500.00
@end smallexample

Why is the Income a negative figure?  When you look at the balance
totals for your ledger, you may be surprised to see that Expenses are
a positive figure, and Income is a negative figure.  It may take some
getting used to, but to properly use a general ledger you must think
in terms of how money moves.  Rather than Ledger ``fixing'' the minus
signs, let's understand why they are there.

When you earn money, the money has to come from somewhere.  Let's call
that somewhere ``society''.  In order for society to give you an
income, you must take money away (withdraw) from society in order to
put it into (make a payment to) your bank.  When you then spend that
money, it leaves your bank account (a withdrawal) and goes back to
society (a payment).  This is why Income will appear negative---it
reflects the money you have drawn from society---and why Expenses will
be positive---it is the amount you've given back.  These additions and
subtractions will always cancel each other out in the end, because you
don't have the ability to create new money: it must always come from
somewhere, and in the end must always leave.  This is the beginning of
economy, after which the explanation gets terribly difficult.

Based on that explanation, here's another way to look at your balance
report: every negative figure means that that account or person or
place has less money now than when you started your ledger; and every
positive figure means that that account or person or place has more
money now that when you started your ledger.  Make sense?