Again, in serious crimes the punishments are also heavy, so that, if the jury pass an unjust sentence and then change their mind, it is impossible to take the opportunity of remedying the mistake; if, on the other hand, they acquit the accused when they ought not to do so, if he lives so circumspectly as never to commit any crime again, how can the jury have made a serious mistake in failing to condemn such a man to death?