In Sophocles' classic play, Haemon tries to reason with his father, Creon, regarding Antigone's fate:"Seest thou, beside the wintry torrent's course, how the trees that yield to it save every twig, while the stiff-necked perish root and branch? And even thus he who keeps the sheet of his sail taut, and never slackens it, upsets his boat, and finishes his voyage with keel uppermost."What "fatal" and tragic character flaw does Haemon's warning address?