I would like to add a few more words of commentary. I am currently working on the Maitrāyaṇīya Upaniṣad (MaiU), which will be published by Bloomsbury Publishers under the provisional title Philosophy and Embodiment: A Cognitive Analysis of the Maitrāyaṇīya Upaniṣad. A cognitive analysis reveals that this text is a brilliantly structured treatise on liberating practice, both in terms of its internal logic and its use of terminology and imagery. I refer to this practice as the threefold practice (vidyā, tapas, cintā; MaiU 4.4: tasmād vidyayā tapasā cintayā copalabhyate brahma).

Thus, I fully agree with Lyne that this description—similarly to BU 2.3 (I discuss this fragment in its full context in Jurewicz 2016/18: 519-228)—is composed from the perspective of liberating knowledge and the practice that actualizes it. From this point of view, one could say that in the perceptible world (mūrta brahman), which is described as false and non-existent (asatya), the manifestation of what is true and existent (satya) is active—namely, the sun and the syllable OM (MaiU 6.3: yad amūrtaṃ tat satyaṃ tad brahma tad jyotiḥ | yaj jyotiḥ sa ādityaḥ | sa vā eṣa OM iti |).

In my analysis of MaiU, I refer to these as material anchors, a term proposed by Edwin Hutchins (1995; see also Sweetser, Stec 2013). According to Hutchins, material anchors are physical objects (such as clocks in the cockpit of an airplane or a ship) that function as metonymic carriers for abstract concepts, whose meaning is shared by a community of varying scope (ranging from pilots in a cockpit to religious practitioners visiting a temple). The sun and the syllable OM, as material anchors, guide the practitioner’s mental and physical activity toward the conceptual target domain of non-perceptible (amūrta) brahman, making them aware that ”below” this perceptible world lies an unmanifest, unknowable reality.

At the same time, the simultaneous designation of these elements as both asatya and satya aims— as Lyne suggests— to express the paradox of the world’s existence as the manifestation of what is unmanifest. This paradox is also reflected, for example, in the meanings of the word aksara, which denotes both ”syllable” (something temporal and perceptible, i.e., manifest) and ”the imperishable” (something beyond time, imperceptible, i.e., unmanifest). These meanings should be activated in the mind simultaneously—a cognitive operation that, at least for my mind, trained in bivalent logic, is impossible to perform spontaneously and requires conscious effort. However, I am convinced that the original audience of Sanskrit texts, for whom these works were composed, activated these contradictory meanings effortlessly, intuitively and in one mental perception. 

From the perspective of practice, it is precisely this paradoxical nature of the existence of the sun and the syllable OM (the fact that they are "asatya satya/satya asatya") that allows them to be regarded as material anchors—perceptible (mūrta) signs that already contain within themselves their imperceptible (amūrta) referent. This is why observing the sun, its movement across the sky, and reciting the syllable OM hold real significance.

With best wishes, 

Joanna

PS. Being aware that it is difficult to buy my previous books, I am attaching the pdfs with a request not to share them.