Final answer:
The assertion that a tragic hero's downfall is brought on by a character defect known as a tragic flaw, or hamartia, is correct. Characters like Oedipus and Creon in Greek tragedies demonstrate this through their excessive pride and arrogance, leading to reversal of fortune and audience catharsis.
Step-by-step explanation:
The statement that the character defect leading to a tragic hero's downfall is known as his tragic flaw is true. According to Aristotle's definition of a tragic hero in his work 'Poetics', a tragic hero possesses a hamartia or a great error, which is the 'fatal flaw' that brings about their downfall. This concept has been exemplified in ancient Greek tragedies, such as the character of Oedipus, whose arrogance and quest for truth led to his demise. likewise, Creon in Sophocles’ Antigone demonstrates hubris, excessive pride, which results in his tragic end. These characters, due to their hamartia, experience a reversal of fortune (peripeteia), come to a realization (anagnorisis), and ultimately lead the audience to experience catharsis.