Step 1: Understanding Nicomachean Ethics.
Nicomachean Ethics is a philosophical work by Aristotle in which he explores the nature of happiness and virtue. He argues that happiness (eudaimonia) is the ultimate goal of human life, achieved through the cultivation of virtue and living in accordance with reason.
Step 2: Analyzing the Options.
- 1. Happiness: This is correct. The primary concern of Nicomachean Ethics is the pursuit of happiness, which Aristotle defines as living a virtuous life in accordance with reason.
- 2. Pleasure: Pleasure is discussed, but it is not the central focus. Aristotle distinguishes between higher pleasures (intellectual pleasures) and lower pleasures (bodily pleasures), placing higher value on the former.
- 3. Duty: Aristotle does not focus on duty in the way some modern philosophers (like Kant) do. He focuses more on virtue and the development of character.
- 4. Good: While Aristotle does discuss the concept of the "good," it is within the context of happiness and virtue, making happiness the primary concept.
Step 3: Conclusion.
The correct answer is 1. Happiness.
Final Answer:
\[
\boxed{\text{The correct answer is 1. Happiness.}}
\]