Reverting to the camp metaphor, when did the camps become two? In dead earnest this occurred when Heidegger burst onto the scene in 1927 with Being and Time. I agree with Peter Simons: "Probably no individual was more responsible for the schism in philosophy than Heidegger." (Quoted in Overgaard, et al., An Introduction to Metaphilosophy, Cambridge UP, 2013, 110.) It is not as if Heidegger set out to split the mainstream whose headwaters were in Franz Brentano into two tributaries; it is just that he started publishing things that the analytic types, who had some sympathy for Heidegger's main teacher Husserl, could not relate to at all.
If I were were to select two writings that best epitomize the depth of the Continental-analytic clash near the time of its outbreak, they would be Heidegger's 1929 What is Metaphysics? and Carnap's 1932 response, "On the Overcoming of Metaphysics Through the Logical Analysis of Language." (In fairness to Carnap, let us note that his Erkenntnis piece is more than a response to Heidegger inasmuch as it calls into question the meaningfulness of all metaphysics.)
To nail my colors to the mast, I take the side of Heidegger in his dispute with Carnap and I heartily condemn the knee-jerk bigotry of the thousands upon thousands of analytic types who mock and deride Heidegger while making no attempt to understand what he is about. The cynosure of their mockery and derision is of course the notorious sentence
Das Nichts selbst nichtet. (GA IX, 114)
The Nothing itself nihilates.
This is the line upon which the analytic bigots invariably seize while ignoring everything else: its place in the essay in question and the wider context, that of Being and Time and other works of the early Heidegger, not to mention the phenomenological, transcendental, existential, life-philosophical, and scholastic sources of Heidegger's thinking.
Now, having called them knee-jerk bigots and having implied what is largely true, namely that the analytic Heidegger-bashers are know-nothings when it comes to Heidegger's philosophical progenitors, and thus having paid them back in their own coin, I will now drop all invective and patiently try to explain how and why Heidegger is not talking nonsense in the essay in question. This will require a series of posts. It will also require some attention and open-mindedness on the part of the reader as well as some familiarity with the two essays in question.
Heidegger's Alleged Violation of Logical Syntax
For Carnap it is obvious that existence and nonexistence are purely logical notions, more precisely, logico-syntactic notions. The sentence 'Cats exist,' for example, does not predicate existence of individual cats. It says no more than 'Something is a cat.' But then 'Cats do not exist' says no more than 'Nothing is a cat.' This sentence in turn is equivalent to 'It is not the case that something is a cat.'
'Nothing,' then, is not a name, but a mere bit of logical syntax. Carnap calls it a "logical particle." (71) And the same goes for 'something.' If I met nobody on the trail this morning, it does not follow that I met somebody named 'nobody.' (Bad joke: I say I met nobody, and you ask how he's doing.) If nothing is in my wallet, that is not to say that there is something in my wallet named 'nothing.' It is to say that:
It it not the case that something is in my wallet
It is not the case that, for some x, x is in my wallet
For all x, x is not in my wallet
~(∃x)(x is in my wallet)
(x) ~(x is in my wallet).
The above are equivalents. It should be obvious then, that in its mundane uses 'nothing' is not a name but a logico-syntactic notion that can be expressed using a quantifier (either universal or particular) and the sign for propositional negation. By a mundane use of 'nothing' I mean a use that presupposes that things exist. Thus when I assert that nothing is in my pocket, I presuppose that things exist and the content of my assertion is that no one of these existing things is in my pocket. (Don't worry about the fact that it is never strictly true that there is nothing in my pocket given that there is air, lint, and space in my pocket.)
I think we can all (including Heidegger) agree that in their mundane uses, sentences of the form 'Nothing is F' can be translated, salva significatione, into sentences of the form 'It is not the case that something is F' or 'Everything is not F.' The translations remove 'Nothing' from subject position and by the same stroke remove the temptation to construe 'nothing' as a name. Not that Heidegger ever succumbed to that temptation.
But now the question arises whether every use of 'nothing' fits the deflationary schema. Is every meaningful use of 'nothing' the use of a logical particle? Consider ex nihilo, nihil fit, 'Out of nothing, nothing comes.' The second occurrence of 'nothing' readily submits to deflation, but not the first. Suppose we write
It is not the case that something comes from nothing.
This removes the quantificational use of 'nothing' in 'Out of nothing, nothing comes' but leaves us with a 'substantive' use. Of course, 'nothing' cannot refer to or name any being or any collection of beings. That is perfectly evident. And Heidegger says as much. But 'nothing' does appear to refer to, or name, the absence of every being. The thought is:
Had there been nothing at all, it is not the case that something could have arisen from it.
The 'at all' is strictly redundant: it merely serves to remind the reader that 'nothing' is being used strictly. Now could there have been nothing at all? Is it possible that there be nothing at all? More importantly for present purposes: Is this a meaningful question? 'Possibly, nothing exists' is meaningful only if 'Nothing exists' is meaningful. So consider first the unmodalized
There is nothing at all
These are perfectly meaningful sentences. That is not to say that they are true, nor is it to say that they are possibly true. Suppose they are not possibly true. Then they are necessarily false. But if necessarily false, then false, and if false, then meaningful. For meaningfulness is a necessary condition of having a truth-value. 'Nothing exists,' then, is a meaningful sentence, and this despite the fact that 'nothing' cannot here be replaced by a phrase containing only a quantifier and the sign for negation.
For Carnap, however, the above are meaningless metaphysical pseudo-sentences because they violate logical syntax. If you try to translate the second sentence into logical notation, into what Carnap calls a "logically correct language"(70) you get a syntactically meaningless string:
This is meaningless because 'exists' cannot serve as a first-level predicate in a logically correct language. Existence is not a property of individuals. 'Exist(s)' is a quantifier, a bit of logical syntax, not a name of a property or of any entity. Therefore, 'Nothing exists' is as syntactically meaningless as the ill-formed formula
~(∃x)(∃x(. . . x . . .)).
Two Interim Conclusions
The first is that Heidegger commits no schoolboy blunder in logic. He does not think that a use of 'Nothing is in the drawer' commits one to the existence of something in the drawer. He cannot be charitably read as assuming that every use of 'nothing' is a referring use. The second conclusion is that Carnap has not shown that every occurrence of 'nothing' can be replaced by a phrase containing a quantifier and the sign for negation. He has therefore not shown that a sentence like 'Nothing exists' is a syntactically meaningless pseudo-sentence.
Heidegger Partially Vindicated
But now the way is clear to ask some Heidegger-type questions.
I showed above that 'nothing' has meaningful uses as a substantive, uses that cannot be eliminated by the Carnap method. And I suggested that 'nothing' could name the total absence of all beings. If this total absence is a possibility, as it would be if every being is a contingent being, then Nothing (das Nichts) would have some 'reality,' if only the reality of a mere possibility. It could not be dismissed as utterly nichtig or nugatory. Nor could questions about it be so dismissed.
One question that Heidegger poses concerns the relation of negation (Verneinung) as a specific intellectual operation (spezifische Verstandeshandlung) to Nothing:
Gibt es das Nichts nur, weil es das Nicht, d. h. die Verneinung gibt? Oder liegt es umgekehrt? Gibt es die Verneinung und das Nicht nur, weil es das Nichts gibt? (GA IX, 108)
Is there Nothing only because there is the Not and negation? Or is it the other way around? Is there negation and the Not only because there is Nothing?
I grant that with questions like these we are at the very limit of intelligibility, at the very boundary of the Sayable. But you are no philosopher if you are not up against these limits and seeking, if possible, to transcend them.