In the same broad stretch of history, thinkers in Greece and in South Asia asked a question we still ask: what is the mind, and is it the same thing as me? Both traditions were full of arguments, not single answers. But a useful contrast shows up. Plato treated the soul itself, with reason in charge, as the person (Plausible; a simplification of his view). Several Indian schools treated the thinking mind, manas, as equipment that a deeper self uses. Both reached for the same picture to explain it: a chariot.
Who was asking, and when?
In Greece, Anaxagoras (about 500–428 BCE) argued that a cosmic Mind (nous) set the universe spinning and organized it (fragment B12) (Sisko & Curd, Stanford Encyclopedia of Philosophy) (Documented as his view). Plato (429?–347 BCE) and Aristotle (384–322 BCE) then built detailed theories of the human soul (Kraut, SEP; Shields, SEP).
In South Asia, the earliest Upaniṣads are generally dated to about 700–500 BCE, and later ones, like the Kaṭha, to about 300–100 BCE (Black, Internet Encyclopedia of Philosophy, §1.a) (Plausible; scholarly estimates). The Buddha is now often thought to have died around 405 BCE (Siderits, SEP) (Plausible; older estimates put him a century earlier).
So the two conversations overlap in time. Did one borrow from the other? That is Unknown from the evidence here. Similar ideas don’t prove copying.
The Greek side: a soul with parts
In the Republic, Plato divides the soul into three parts: reason, which loves knowledge and truth; spirit, drawn to honor; and appetite, which wants food, drink, and sex (Lorenz, SEP “Ancient Theories of Soul”). His argument: people are sometimes thirsty yet refuse to drink, so he distinguishes the impulse to drink from the resistance to it (Republic 439c–d, Shorey trans.). In a later dialogue, the Timaeus, he locates spirit between the midriff and neck (70a, Lamb trans.) (Documented as Plato’s view).
Plato also has his chariot. In the Phaedrus, the soul is a charioteer with two winged horses (246a–b). One horse follows reason and honor; the other resists control (253d–e, Fowler trans.). In the Phaedo, Plato’s Socrates argues that the soul exists before and after the body and returns to animate another one; Lorenz notes the Pythagoreans also held versions of rebirth (Lorenz). Not every Greek agreed; this was one school’s view.
Aristotle took a different line. He described the soul as the form of a living natural body, and said asking whether soul and body are one is like asking whether wax and the shape a stamp gives it are one (De anima II.1, Smith trans.). The soul isn’t a passenger riding inside. He also separated thinking from perceiving: all animals perceive, he said, but practical thinking belongs to only some of them (De anima III.3, Smith trans.).
The Indian side: the mind as an instrument
The Upaniṣads talk a lot about ātman, the self. Brian Black notes the word first meant things like “breath,” “spirit,” or “body,” and later came to mean essence, consciousness, or ultimate reality (Black, §3).
The Kaṭha Upaniṣad has its own chariot. Paraphrasing Max Müller’s 1884 translation: the self rides in the chariot; the body is the chariot; buddhi (Müller: “intellect”) is the charioteer; manas, the mind, is the reins; the senses are the horses (Kaṭha 1.3.3–4; Müller, pp. 12–13). Here the mind is not the rider. It’s the reins.
Later schools made this more technical:
- Sāṃkhya. Īśvarakṛṣṇa’s Sāṃkhya Kārikā (verse 33) says the “internal instruments are three”: intellect, ego-sense (ahaṃkāra), and mind (Colebrooke trans., 1837, p. 111). These belong to nature. The true self, puruṣa, is consciousness, separate from them.
- Vedānta. Much later, Sadānanda’s Vedāntasāra speaks of four “internal organs”: mind, intellect, ego, and a fourth G. A. Jacob translated as “thinking” (citta, often rendered memory or mind-stuff) (Jacob trans., 1888, p. 5 n. 2, pp. 58, 66, 68 n. 2). So the familiar four-part “inner organ” is a later Vedānta list, not the Upaniṣads’ own.
- Yoga. The Pātañjalayogaśāstra, which scholar Philipp Maas dates to the late 4th or early 5th century CE, is the oldest surviving systematic Sanskrit account of Yoga from a Brahmanical perspective (Maas, full text, p. 66) (Plausible; his dating).
Not everyone agreed about the self, either. In one Pāli discourse, the Buddha tells monks that form, feeling, perception, choices, and consciousness are each “not-self” (SN 22.59, Sujato trans.). Śaṅkara (about 700 CE), the best-known teacher of Advaita Vedānta, argued the self and ultimate reality (brahman) are one. He was its main champion, not its founder; the Brahma Sūtra he commented on is centuries older (Black, §8).
Same chariot, different rider
Put the two chariots side by side:
| Plato (Phaedrus) | Kaṭha Upaniṣad | |
|---|---|---|
| Who is the charioteer? | Reason, part of the soul | Buddhi, intellect |
| Who is the real “you”? | The soul itself | The self who rides as passenger |
| What’s the goal? | Reason guiding the soul toward truth | Reaching a place beyond rebirth |
An analogy, not a translation: for Plato, you’re the driver handling two different horses. For the Kaṭha, you’re the passenger, and even the driver is equipment.
This is a contrast of emphasis, not a law. Aristotle didn’t fit Plato’s picture, and Buddhists rejected the Upaniṣads’ lasting self. Both “sides” argued with themselves.
How we know
What survives. Greek texts copied by hand for centuries; Upaniṣads composed and passed on by recitation long before being written. Most readers meet both in translation, and every translator chose words like “soul,” “mind,” and “intellect.” Anaxagoras’s ideas survive only in quotations by later writers.
Whose voices are missing. These selected texts cannot represent everyone in Greece or South Asia. Nor were all the voices male: Black discusses the women Gārgī and Maitreyī in the Upaniṣads (Black, §§3, 6).
How later readers used it. Aristotle’s On the Soul traveled into Arabic. Ibn Rushd (Averroes, 1126–1198) wrote three separate commentaries on it (Ben Ahmed & Pasnau, SEP “Ibn Rushd”).
Then vs. now
Then: For Plato, the reasoning soul was the self; for the Kaṭha and Sāṃkhya, mind and intellect were instruments of a deeper self; for Buddhists, no lasting self was found in any of them.
Now: The U.S. National Institute of Neurological Disorders and Stroke says all sensations, movements, thoughts, memories, and feelings result from signals passing through neurons (NINDS) (Strongly supported). Neither ancient model is a map of the brain. Whether consciousness is fully physical is still argued: in the 2020 PhilPapers Survey, about 52% of 1,733 responding philosophers leaned toward physicalism (the view that the mind is entirely physical) and about 32% toward non-physicalism (PhilPapers) (Disputed). Rebirth and liberation are religious teachings; this page describes them rather than testing them.