The suggestion that ultimate truth cannot be expressed, and that Nāgārjuna does not affirm any proposition, might appear to jar with the account given above of emptiness
as the negation of svabhāva. If the doctrine of emptiness simply affirms the proposition,"things do not have svabhāva" ultimate truth appears to be expressible after all.
Yet, as we have seen, the negation of svabhāva, is not an expression of ultimate truth. It is only one expedient method for reducing the tendency to reify objects, and to grasp at their existence, which constitutes the extreme of eternalism. There is also the extreme of nihilism to avoid, that is, the belief that nothing really exists at all, or else, that everything will ultimately be annihilated. Due to its emphasis on negation, the Madhyamaka has often been interpreted as implying such a position.
The "medicine" of emptiness, though,can perform two functions; it negates svabhāva when one grasps at existence, and it negates nonexistence if one happens to be a nihilist. Nāgārjuna tells us about this in chapter 18:
That there is a self has been taught
And the doctrine of no-self
By the Buddhas, as well as the
Doctrine of neither self nor nonself (MMK 18:6; Garfield 1995, 49).
In other words, emptiness negates both the inherent existence of the self as well as its
inherent nonexistence, and it does the latter, apparently by affirming the self once again.
As we shall see in the next section, the Yogācāra adopted this technique, and reaffirmed
svabhāva. All this suggests, then, that none of the Buddha‘s claims can ever be taken as
ultimate or final, and that he can preach any doctrine whatsoever in order to correct his listeners‘ mistakes. As one author puts it, the Buddha‘s method is to disparage anything that sentient beings cling to and to extol the opposite as supreme (Liu 1993, 660).
Emptiness then, is not just the negation of svabhāva, but also the negation of anything at all that one might become attached to and construct theories about; in short, it requires the relinquishing of all views.
Rather than a theory of metaphysics, it is a soteriological device, aimed at reducing delusion, and the purpose of meditation on emptiness is to push the practitioner into a state of non-attachment, non-craving, and non-grasping.