To err is human, but to persist in the mistake is ugly.

To err is human; to admit it, superhuman.

To err is human. To blame someone else is politics.

To err is human, but it feels divine.

To err is human; but contrition felt for the crime distinguishes the virtuous from the wicked.

To err is human also in so far as animals seldom or never err, or at least only the cleverest of them do so.

To err is human - and to blame it on a computer is even more so.

To err is human, but to really foul things up you need a computer.

To err is human, to purr feline.