When we speak about voidness, which is the translation term that I prefer over “emptiness,” it refers to an absence of a way of existing that does not exist, which never existed and never will exist. We project impossible ways of existing onto ourselves, others and all phenomena that don’t correspond at all to reality. Something corresponding to them is totally absent. To use a simple example, if we imagine that we exist as the most important person in the universe, who must always have his or her way, this is a total fantasy. Nobody exists in that impossible way. There is a total absence of that way of existing with regard to anyone.
Let me explain why I use “voidness” rather than “emptiness.” I don’t know about other languages, but in English there is a subtle difference between the two terms. “Emptiness” implies that there is a container – a glass for instance – and that it is empty. In other words, there is a basis or container for the emptiness and there it is, a findable and self-established container in terms of conventional truth. “Emptiness,” then, refutes or negates something about it – that there was anything ever in it, specifically an impossible way in which this findable, self-established container ever existed.
This description suits the so-called “lower tenet systems” – those less sophisticated than Prasangika. All these non-Prasangika systems assert that the existence of all validly knowable phenomena is established by the fact that each such phenomenon has an individual defining characteristic mark on its own side that makes it an individual validly knowable item. They also assert that their existence is established by the fact that they can be found as referent "things" corresponding to the names and concepts for them. This latter manner of establishing the existence of something is known as "existence established by a self-nature" or “self-established existence” for short. Many translators render this term as “inherent existence.”
In all tenet systems, the absence of an impossible way of existing is an imputable knowable phenomenon. It can only be known by first cognizing its basis for imputation. According to the non-Prasangika systems, however, to validly cognize some object – in this case, the basis for the imputation of an absence – we need to apprehend something on the side of that object that establishes its existence and only then can we validly know it as a validly knowable phenomenon.
- For Vaibhashika and Sautrantika, the voidness – or more appropriately, the selflessness of persons – can only be cognized with the basis for imputation of this selflessness appearing and being cognized simultaneously with it. In this case, the basis is the five aggregates together with the conventionally established person as an imputation on them as its basis. To use our analogy of an empty glass, according to these Hinayana systems, we can only focus on there never having been anything in the glass by focusing at the same time on the glass with nothing inside it.
- Similarly, for Chittamatra and Svatantrika, the voidness of all phenomena can only be cognized with its basis for imputation appearing and being cognized first. But, while focusing on this voidness, the basis no longer appears. According to these Mahayana systems, we focus first on the glass with nothing inside it and then focus only on the fact that there has never being anything inside the glass.
Prasangika follows this model of Chittamatra and Svatantrika – first the basis of imputation of a voidness appears and then its voidness appears without the basis appearing any longer. However, to apprehend the basis for voidness does not require apprehension of something on the side of the basis that establishes its existence. This is because Prasangika refutes that either the conventional individual defining characteristic or the conventional self-nature of anything has the power to establish the existence of that object either by its own power or in conjunction with mental labeling.
Therefore, with Prasangika, it is not the case first apprehending a glass, the existence of which is self-established, and then refuting an impossible way of existing of that self-established glass. That would be apprehending that the glass is empty. According to Prasangika, we apprehend the glass without affirming anything about the manner in which its existence is established.
This assertion accords with the Prasangika rejection of the logic used by Svatantrika and the other lower tenet systems to refute impossible ways of existing. Those systems assert the self-established existence of the topic of any syllogism – the so-called “property-possessor” – used in the refutation, but since Prasangika does not accept the self-established existence of anything, they do not share a topic in common with these systems in order to debate with them using their system of logic. For that reason, Prasangika only argues using absurd conclusions, prasanga.
In short, Prasangika does not assert anything findable and self-established even in terms of conventional truth. It simply asserts that there is no such thing as an impossible way of existing with regard to anything. It doesn’t negate that way of existing from something conventionally findable.
I choose “voidness,” then, rather than “emptiness,” to fit the Prasangika view. The Sanskrit term for voidness, shunyata, comes from the Sanskrit word for zero. It means “a nothingness,” in the sense of “no such thing.” It's not that there is something firmly established, but it's empty of something else that never existed. On the other hand, voidness as a nothingness is not the total negation of everything. It is not a nihilistic term. It is just a total absence of something findable corresponding to our projection of something impossible that could never exist.