Good : Bad :: Virtue : ? — Identify the antonym that pairs with 'Virtue' in the same way that 'Bad' pairs with 'Good'.

Introduction / Context:
Antonym analogies require selecting the direct opposite within the same semantic field. 'Good : Bad' sets the polarity. We must choose the precise opposite for 'Virtue'.

Given Data / Assumptions:

• Good ↔ Bad are direct antonyms.
• Virtue denotes moral excellence or goodness of character.
• We seek the standard antonym used in ethics/morality.

Concept / Approach:
In moral philosophy and common usage, the opposite of virtue is 'vice'—a bad habit or immoral conduct opposing virtuous traits.

Step-by-Step Solution:
1) Preserve relation: concept ↔ direct antonym.2) Virtue ↔ Vice is the canonical pair.3) Select 'Vice'.

Verification / Alternative check:
Dictionaries and ethics texts list vice as the contrary to virtue (e.g., temperance ↔ intemperance, honesty ↔ dishonesty under the vice–virtue framework).

Why Other Options Are Wrong:

• Blame: Not the opposite of virtue; relates to responsibility.
• Sin/Evil: Related to wrongdoing but not the strict antonymic pair in classical phrasing.
• Despair: An emotional state; unrelated.

Common Pitfalls:
Picking a generally negative word (sin/evil) rather than the exact antonymic counterpart (vice).

Final Answer:
Vice