Ancient philosophy is philosophy in antiquity, or before the end of the Roman Empire. It usually refers to ancient Greek philosophy. It can also encompass various other intellectual traditions, such as Chinese philosophy, Indian philosophy, and Iranian philosophy. Ancient philosophies are generally deeply rooted in religious traditions. Accordingly, ancient philosophies have a comprehensive outlook as opposed to modern or contemporary philosophies, which tend to have more narrow methodologies and areas of focus.

In the Western tradition, ancient philosophy was developed primarily by Socrates, Plato, and Aristotle. Ancient philosophy, however, also includes the Pre-Socratics, Hellenistic philosophy, and Roman philosophy. Ancient philosophy in the West is distinguished from Medieval philosophy, which was largely influenced by Christianity and Islam. Ancient philosophies from non-Western traditions, such as Chinese or Indian philosophy, often have strong ethical or religious concerns that continue to be major parts of the traditions today.

The term ancient philosophy encompasses a variety of thoughts that emerged from the early stages of various intellectual traditions. However, not all ideas are considered philosophies since philosophy includes, as its primary component, a rational self-refection and conceptualization of thought.

Major philosophies include: ancient Greek and Roman philosophy in the West, which date approximately from the sixth century B.C.E. through the third century C.E.; Chinese philosophy including Yin-yang philosophy, Taoism, Confucianism; Indian philosophy including Upanishads and Vedic traditions, Jainism, Buddhist philosophy, and Hindu philosophy; and ancient Iranian philosophy including Zoroastrianism.

Ancient philosophy tends to have a comprehensive perspective which includes a wide range of components, including myth, religious beliefs, ethics, literature, cosmology, and theories of nature. The synthetic characteristic of ancient philosophy is different from modern and contemporary philosophies in that modern and contemporary philosophies tend to focus on specific, often narrower, areas and their approaches are accompanied with better methodological awareness. Because of its synthetic character, thought processes found in ancient philosophy also differ from those of modern philosophy. For example, the Pre-Socratics in ancient Greek philosophy presented their metaphysical arguments in poetic verse and their arguments are mixed with religious-ethical themes such as divine justice and salvation of the soul. In ancient Chinese philosophy, metaphysics is also fused with natural philosophy, ethics, and is often extended to political philosophy. Because of this comprehensiveness, the interpretation of ancient philosophy requires an understanding of an entire framework of thought, history, and culture.

Ancient philosophy is often deeply intertwined with religious traditions. Modern and contemporary philosophy tend to develop philosophy as an autonomous discipline independent of religious traditions. This is evident in modern and contemporary Western philosophy. Ancient Indian philosophy, for instance, is deeply rooted in Upanishad, Vedas, Hinduism, and other texts. Plato’s philosophy is built within a framework that presupposes the immortality of the soul, redemption, and divine justice.

Ancient philosophy in the West refers to philosophies that date from approximately the sixth century B.C.E. to about the third century C.E. and includes the philosophies of the Pre-Socratics, Socrates, Plato, Aristotle, and those developed in Hellenistic and Roman periods.

The pinnacle of ancient philosophy is the classical Greek philosophy as developed by Plato and Aristotle. These two philosophers defined the issues, philosophical vocabularies, methodologies, and types of discourses of philosophy as a discipline and influenced the entire tradition of philosophy. Their philosophies are far more comprehensive than those of other philosophers in antiquity.