If one were forced to sum up the whole of Buddhist ontology in three words, one could perhaps not do better than to write: impermanence, emptiness, suffering. In a sentence: all (samsaric) items are impermanent (anicca), selfless (anatta), and unsatisfactory (dukkha). If that is too quick for you, see here for a more leisurely and scholarly account.
Some self-referential difficulties attaching to impermanence were addressed in a
previous post. Now let's see whether similar difficulties are to be found in the doctrine of
anatta/anatman when this is taken unrestrictedly. Roughly, the doctrine so construed has it that
nothing possesses self-nature, own-being, substantiality. So let us consider
1. All is empty.
One will be tempted to say that (1) is self-refuting. For if all is empty, then (1) is empty, in which case we are not in the presence of any one, self-identical, determinate thesis with a determinate truth-value. But that is presumably not what is intended by someone who asserts (1). Such a person intends (1) as a determinate thesis that is true. Not only that, the person intends the thesis to be always true and necessarily true. The idea behind (1) is not that it is true now but was perhaps false in the past and will again be false in the future. The affirmer of (1) is not countenancing the possibility that if we just wait long enough some nonempty things will emerge. Nor does the proponent of (1) intend it as contingently true. She is not saying, "It is true in the actual world, but there are a myriad of possible worlds in which it is false." Or, "(1) just happens to be true, but it might have been false." The idea is rather that (1) captures a temporally and modally invariant structure of beings qua beings.
But if so, then (1), if true, is false. So the proponent of (1) must retreat to an empty emptiness doctrine, so to speak, to a relativized version of (1) according to which all is empty including (1) itself.
Now is that a problem for the proponent of (1)? I argued elsewhere that relativized alethic relativism is severely problematic. But what about the present case? Is emptied emptiness -- to give it a name -- coherently maintainable?
I should think there is a serious problem. The earlier difficulty was that, if (1) is true, then it is false. Now the difficulty is that, if (1) is true, then (1) is meaningless. For if it is granted that (1) is empty, then (1) lacks self-nature, a determinate identity, a definite sense or meaning in consequence of which it cannot be either true or false. The problem now is not that (1) proves itself to be false, but that it proves itself to be truth-valueless, which is tanatamount to its being meaningless and no proposition at all.
Michael Krausz, however, thinks there is no problem. He writes,
. . . if the doctrine of emptiness is itself 'empty' then it does no harm to the situation it paradoxically addresses. Rather, the doctrine becomes non-assertable; utterance of it becomes only 'empty' sound. It may be that everything is empty but one cannot assert that. (Bilimoria and Mohanty, p. 102)
Krausz's idea (which he credits to Matilal) is that (1) proves its own non-assertibility. (1), though not assertible as true, might be true nonetheless. It is merely the assertibility of (1) that is problematic, not its truth. It can therefore be coherently maintained that (1) is true just so long as one is careful not to assert (1).
Compare
2. No statement is negative.
(2) applies to itself and so appears to refute itself: if (2) is true, then it is false. But consider a possible world W in which God destroys all negative statements and makes it impossible for anyone to make a negative statement. In W, (2) is true, but non-assertible. (2) does not prove itself to be false; it proves itself to be non-assertible. So why not say the same thing about (1)?
But this defense of (1) will not work. For what (1) implies is that everything is empty or devoid of self-nature: every act of assertion, indeed every speech-act, every content asserted, and every linguistic and other means used to encode or express propositional contents. The problem, therefore, is not just that the speech-act of stating or asserting (1) is self-defeating, but that the propositional content asserted is inconsistent with this content's being true.
And the same goes for any truth-maker you care to introduce. If you distinguish the proposition that all is empty from the fact that makes this truth-bearer true, then the emptiness extends to this truth-maker as well.
So the the analogy between (1) and (2) fails, and (1) collapses either into falsehood or into truth-valuelessness/meaninglessness.
(1) simply must be rejected. This is not to say that a restricted anatta/sunya thesis is not defensible. But (1) in its restricted form, as applying to everything, is indefensible.