Philosophy and literature involves the literary treatment of philosophers and philosophical themes (the literature of philosophy), and the philosophical treatment of issues raised by literature (the philosophy of literature).
Strictly speaking, the philosophy of literature is a branch of aesthetics, the branch of philosophy that deals with the question, "What is art"? Much of aesthetic philosophy has traditionally focused on the plastic arts or music, however, at the expense of the verbal arts. Much traditional discussion of aesthetic philosophy seeks to establish criteria of artistic quality that are indifferent to the subject matter being depicted. Since all literary works, almost by definition, contain notional content, aesthetic theories that rely on purely formal qualities tend to overlook literature.
The very existence of narrative raises philosophical issues. In narrative, a creator can embody, and readers be led to imagine, fictional characters, and even fantastic creatures or technologies. The ability of the human mind to imagine, and even to experience empathy with, these fictional characters is itself revealing about the nature of the human mind. Some fiction can be thought of as a sort of a thought experiment in ethics: it describes fictional characters, their motives, their actions, and the consequences of their actions. It is in this light that some philosophers have chosen various narrative forms to teach their philosophy (see below).
Plato, for instance, believed that literary culture had a strong impact on the ethical outlook of its consumers. In The Republic, Plato displays a strong hostility to the contents of the culture of his period, and proposes a strong censorship of popular literature in his utopia.
More recently, however, philosophers of various stripes have taken different and less hostile approaches to literature. Since the work of the British Empiricists and Immanuel Kant in the late eighteenth century, Western philosophy has been preoccupied with a fundamental question of epistemology: the question of the relationship between ideas in the human mind and the world existing outside the mind, if such a world exists.