Before you begin The Upanishads were not written to be read the way you read a textbook. They are pointing at something — and the pointing only works if you bring a certain quality of attention to the reading. Not effort. Not striving to understand. Just honest looking. The tradition says the first qualification is viveka — the capacity to ask, with genuine curiosity: is this the self, or is this something the self observes?
If you are completely new After the foundations — the classical sequence

The traditional Advaita study sequence follows what the tradition calls the prasthānatrayī (threefold starting point) — Upanishads, Bhagavad Gītā, Brahmasūtras — supplemented by Śaṅkara's prakaraṇa granthas (independent treatises).

Two approaches — which fits you?

Conceptual approach

Start with the concept pages and use the Upanishad texts to illustrate them. Good if you prefer to have the framework before the examples. Begin: What is Brahman? → What is Ātman? → Ātman-Brahman Identity → Māyā → the Mahāvākyas. Then read the Upanishad passages that illustrate each concept.

Textual approach

Start with the Upanishad texts and let the concepts emerge from them. Good if you prefer to encounter the teaching as it actually appears, without a pre-arranged framework. Begin: Īśā → Māṇḍūkya → Kaṭha → Chāndogya. Visit concept pages when a term needs clarifying.

How to use the three reading levels

Every verse and concept page on this Codex has three reading levels: Curious, Exploring, and Deep Dive.

Curious is for the first reading. It gives you the essential point without requiring prior knowledge. Read it without effort — just follow the logic. If it makes sense, good. If it does not, read it again. If it still does not, that is also good: the not-understanding is information about where your inquiry actually is.

Exploring is for the second reading, usually on a different day. It introduces the Sanskrit terminology and the philosophical framework. This is where the concepts become more precise — and where the first confusions often arise that are worth sitting with.

Deep Dive is for when you have read the Curious and Exploring levels and want to engage the primary sources, the scholarly debates, and the technical analysis. Not everyone will need this level. But for those who want to engage Advaita as a rigorous philosophical system rather than just a set of insights, this is where the precision is.

What the tradition says about the inquiry itself

The Advaita tradition is explicit: reading about Advaita is not the inquiry. It is preparation for the inquiry. The inquiry itself is the direct question: what is the self? Not asked theoretically. Asked about what is actually present right now, as you read this sentence — the awareness in which these words appear.

The tradition recommends three stages: śravaṇa (hearing the teaching), manana (reflecting on it until no doubt remains), and nididhyāsana (deep contemplation until the recognition is stable rather than intermittent). This Codex supports the first stage and points toward the second. The third is not something that happens on a website. But the first two, done honestly, can clear the way for it.