The key philosophical themes in Western philosophy topics of Paper I are:

1. Metaphysics:
Metaphysics deals with the nature of reality and the fundamental questions about existence, causality, and identity. It explores topics such as the nature of being, substance, time, space, and the relationship between mind and body.

2. Epistemology:
Epistemology focuses on the nature of knowledge and how we acquire it. It examines questions related to skepticism, rationalism, empiricism, and the limits of human understanding. Topics in epistemology include the nature of truth, justification, perception, and the reliability of knowledge.

3. Philosophy of Mind:
The philosophy of mind explores the nature of consciousness, mental states, and the relationship between the mind and the body. It delves into questions about the existence of the self, the nature of subjective experience, and whether mental states can be reduced to physical processes.

4. Philosophy of Language:
The philosophy of language examines the nature and structure of language, its relationship to thought and reality, and the limits of language. It explores questions about meaning, reference, communication, and the role of language in shaping our understanding of the world.

5. Moral Philosophy:
Moral philosophy, also known as ethics, addresses questions about what is morally right or wrong, and how we ought to live. It explores different ethical theories such as consequentialism, deontology, and virtue ethics. Topics in moral philosophy include questions about moral responsibility, the nature of good and evil, and the foundations of moral judgments.

6. Political Philosophy:
Political philosophy examines the nature and justification of political systems, the role of the state, and the rights and responsibilities of individuals within society. It explores questions about justice, equality, freedom, and the relationship between the individual and the community.

7. Philosophy of Religion:
The philosophy of religion explores questions about the existence and nature of God, the problem of evil, religious experience, faith, and reason. It examines different arguments for and against the existence of God and explores the relationship between religion and morality.

8. Philosophy of Science:
The philosophy of science examines the nature of scientific knowledge, the methods of scientific inquiry, and the relationship between science and other areas of knowledge. It explores questions about scientific realism, the nature of scientific explanation, and the limits of scientific understanding.

These key philosophical themes encompass a wide range of topics and provide a foundation for understanding and critically analyzing the major issues in Western philosophy.