Ogden Nash. (№ 263790)

Long known to every schoolboy and even every academic woman if she
science is not deaf, -
What in the world there are two kinds of sin.
The first type is called a Sin of Commission, and as easy to guess,
He is committing what to do not necessary;
And the second type is the opposite of the first, and it's called the Sin of Omission and
is considered no less serious...
<...>
Compared to the first the second kind of sin - the Sin of Omission - dim and pale,
But he is the most malicious.
What causes true suffering?
The unpaid contributions outstanding invoices, unexecuted insurance, unwritten
letters, wasted chances and missed dates.