Final answer:
Atticus calls Mrs. Dubose a great lady because she beat her morphine addiction.
Step-by-step explanation:
Atticus calls Mrs. Dubose a great lady because she beat her morphine addiction. In the book 'To Kill a Mockingbird' by Harper Lee, Mrs. Dubose is depicted as a strong and courageous woman who overcomes her addiction with Atticus's help. Her struggle with addiction and her determination to fight it make her a great lady in Atticus's eyes.