Final answer:
Atticus is driven to defend Tom Robinson because it aligns with his professional duty as a lawyer and his personal ethical code, not for recognition or to fight systemic issues directly.
Step-by-step explanation:
Atticus feels compelled to defend Tom Robinson because he holds his professional duty as a lawyer in high esteem and adheres to his own moral compass. The decision is deeply entrenched in his personal ethics which dictate his actions both as a professional and as a member of the Maycomb community. He believes in the importance of upholding the law and providing diligent representation, regardless of the public opinion. Contrary to merely challenging the town's prejudice or seeking personal accolades, Atticus is motivated by an unyielding commitment to justice and to setting a good example for his children, demonstrating the imperative of doing what is right in spite of opposition.
Through the character of Atticus, To Kill a Mockingbird explores themes like individual conscience, moral courage, the role of a lawyer, and the demands that come with upholding one's personal and professional integrity.