Philosophy is a vast subject that encompasses a wide range of thinkers and philosophers. While it is not possible to provide an exhaustive list, here are some key figures that you can consider studying as part of your syllabus. Remember, this list is not comprehensive, and you may encounter other philosophers depending on the specific requirements of your course.

1. Ancient Greek Thinkers:
- Socrates: Known for the Socratic method and his emphasis on questioning and self-examination.
- Plato: Disciple of Socrates, famous for his theory of Forms and his political work, "The Republic."
- Aristotle: Student of Plato, contributed to various fields such as ethics, politics, and metaphysics.

2. Enlightenment Philosophers:
- René Descartes: Known for his famous statement, "I think, therefore I am," and his dualistic philosophy.
- John Locke: Influential in political philosophy, popularized the concept of natural rights and social contract theory.
- Immanuel Kant: Developed the philosophy of transcendental idealism and emphasized reason as the basis for ethical behavior.

3. Existentialist Thinkers:
- Søren Kierkegaard: Considered the father of existentialism, focused on individual choice and subjective experience.
- Friedrich Nietzsche: Critiqued traditional morality and religion, emphasized the concept of the "Ubermensch" or Superman.
- Jean-Paul Sartre: Argued for the existence of human freedom and responsibility, popularized the phrase "existence precedes essence."

4. Political and Social Thinkers:
- Karl Marx: Known for his socialist and communist theories, particularly in "The Communist Manifesto" and "Das Kapital."
- John Stuart Mill: Advocate of individual liberty, utilitarianism, and women's rights.
- Hannah Arendt: Examined the nature of power, authority, and totalitarianism in works like "The Origins of Totalitarianism."

5. Modern Philosophers:
- Ludwig Wittgenstein: Analytic philosopher who explored the relationship between language and thought.
- Michel Foucault: Studied power and knowledge, focused on the institutions and systems that shape society.
- Judith Butler: Known for her work on gender and identity, particularly in "Gender Trouble."

Remember, this list is not exhaustive, and there are many other influential thinkers and philosophers you may encounter in your studies. It is essential to understand the key ideas and contributions of each philosopher and how they have shaped the field of philosophy.