A common charge against the Indian textual tradition is that it is a contradictory heap—Vedas that ritualise, Upanishads that renounce, Darshanas that argue, Tantras that transgres…
Start with the sense of contradiction and it usually dissolves into a sense of level.
Here is what makes the coherence more than a comforting story. The tradition did not merely assert that its knowledge held together.
The hardest case for the "coherent architecture" claim is Tantra, which can look like a rebellion against Vedic order.
The Vedas, Upanishads, Darshanas and Tantras look like a contradictory pile of texts. Look closer and a single coherent architecture appears. Here is how it holds together.