In Harvey P. Alper’s seminal paper on Śiva and the ubiquity of consciousness (1979), he writes on the many paradoxes in Abhinava’s Tantrā-loka (950 A.D.).
Here, I list three of those issues.
1) The personal vs impersonal
In Abhinava's synthesis the personal and impersonal are juxtaposed in such a way that the latter appears as an outgrowth of the for the former. (351)
Alper claims that the question of ‘ordinary life’ and ‘transcendence’ is juxtaposed. If there is non-duality, then self-enquiry and the impersonal (no response/emotion/reactivity), can not be both active and present in a yogic path. Śiva is I-consciousness, then why should one practise yoga? Or, in other words, isn’t the manipulation of energy in the subtle body affecting one’s position in the world, causing some mode of transformation/cause and effect? So then, it is not organic, but a forced manipulation of self-transformation. Thus, interfering with causality or ‘God’s plan’/ the natural laws of the universe.
2) Abhinava’s avoidance of Ultimacy
In this way he seems to achieve physics which avoids strict dualism or strict monism, which allow sort of ordinary epistemic interaction whose legitimacy he does not wish to surrender, and which avoids opting for any one unsublatable description of ultimacy. (366)
Again, developing on my last point, the world is God/Śiva. The yogi is Śiva, and the cosmos. But there is still a separation between these entities between self (Atman), Śiva (God), and the Universe. If he is both and neither, then there is ultimately a void, which is a Buddhist teaching. If it is both and neither, it still fluctuates between a choice in presenting these two absolute outcomes.
3) The Ordinary vs Extraordinary
The yogic analogy reveals, too, that just as Abhinava's epistemological problem depends for its solution on a set of metaphysical assertions, so these assertions themselves depend upon a religious validating of human experience, ordinary and extraordinary. (366)
How would one determine 'the extraordinary' from the ‘ordinary’ in non-dual metaphysics? If everything is united, then the attainment of Yoga contradicts this ‘ordinary position’ and renders it as inferior, as the attainment of Yoga leads to extraordinary outcomes (liberation). It is a step-by-step guide to Moksha. Therefore, by validating one's own awakening, the Yogi becomes separate and is subjected to being external - outside ‘the ordinary’, and, thus, bringing them out of one-ness.