An interesting paper by Abraham D. Stone on Carnap’s and Heidegger’s different, though in some ways symmetrical responses to Husserl (still unpublished, as far as I know), concludes with some pronouncements on Carnap’s conception of the task of philosophy that appear superficially plausible but don’t in the end quite cohere:
Whereas for Heidegger, then, the remedy for impropriety is to heed the call of conscience which turns us back out of curiosity and towards the true end, what Carnap demands is that we overcome our despair in faith: “the faith that the future belongs to this attitude [Gesinnung]” (Aufbau Preface, p. xvi). The task of philosophy, in this context, is not to turn us back toward, or to make explicit, primordial fore-givenness, but rather to prepare the formal means by which we can choose the language we will need for our tasks, and whose univocality will result, not from its responsibility to such fore-givenness, but from its correctly chosen conventionality: that is, from its responsibility to our ultimate end. And this means, finally, that what philosophical terminology needs in the way of fixed sense is not truth (correspondence to what the object essentially demands), but merely correctness, Richtigkeit, which in turn comes down to convenience, suitability for our (absolute) end, our finitude: Zweckmäßigkeit.
Before going on about this, though, I need to clarify that for Stone, “Carnap” is pretty much exclusively, up to this paragraph, the Carnap of the Aufbau. (Whether the Heidegger is also exclusively the Heidegger of Sein und Zeit I can’t say.) While the Aufbau-Carnap lacks the full-scale logical or linguistic pluralism of the Syntax-Carnap, I am sympathetic to Michael Friedman’s argument (cf. esp. his own paper in the Cambridge Companion to Carnap) that more of that later pluralism is prefigured in the Aufbau than is usually acknowledged.
What is certainly prefigured in the Aufbau is something Michael does not mention (but would presumably acknowledge): the (Kantian or at least quasi-Kantian) Primat der praktischen Philosophie, i.e. subordination of Verstand to some broader conception of Vernunft — in other words, the pragmatic criterion for language choice at the level of the metatheory, which one associates with the Syntax, and eben nicht with the Aufbau. This may sound hard to believe, but it’s expressed very clearly in §105, a remarkable passage on “the problem of deducing the constitution rules [der Deduktion der Konstitutionsregeln]” that, as far as I’m aware, has not much been discussed (outside my book, pp. 175-77).
Carnap here explicitly speculates that the general rules of constitution of the kind he has listed in the previous section might be deducible from some single principle, on the analogy of a ‘world formula’ of the kind imagined by Laplace, from which all the laws of physics can be derived: “In the present case, as in that one, the highest principle is not known, but in the first instance provides rather a goal or direction for research, a goal whose attainability is not even assured.” Wow — this sure ain’t the textbook Carnap! But he actually goes considerably further:
If the highest principle of construction were already known, a further task would consist in determining how it can be understood as necessarily resulting from the point of knowledge, or more precisely, from the contribution of knowing to the more comprehensive context of human life purposes [für den umfassenderen Zweckzusam- menhang des Lebens], that the shaping of experiences into objects occurs precisely in the way it is represented to do in the constitution system, in the way it is given expression by the general constitution rules, and finally in the way it is summed up most concentratedly in the highest constitution principle.
Which is presumably what Philipp Frank had in mind when he wrote to Carnap, on first reading the Aufbau, “What you advocate is pragmatism.” So there is continuity in this respect between Aufbau and Syntax, but also a major difference. In the passages just quoted, it’s assumed that human reason is capable, Leibniz-like, of arriving at a single or unique “highest constitution principle” by pure reason. The principle of tolerance, four years later, does not proscribe that possibility, but sets it aside as irrelevant, and implicitly abandons the idea that there is, or could be, a unique Zweckzusammenhang des Lebens from which to deduce such a principle.
Back to Stone: is there, then, a sense in which the Aufbau-Carnap sees the task of philosophy as “preparing the formal means by which we can choose the language we will need for our tasks”? Perhaps one could invoke Thomas Mormann’s argument that Carnap still holds a cognitivist view of ethics in Aufbau §152 (can one can connect this with §105’s “more comprehensive context of human life purposes”?) to claim that the Leibnizian rationalism in the background involves a “calculemus!” approach to practical choices, i.e. we make such choices by “formal means.” Okay, I doubt it (for reasons I won’t expand on just now), but even if we granted this improbable interpretation, what are we to make of Stone’s final sentence?
He says there that “responsibility to our ultimate end” is to be understood as “correctness [Richtigkeit]” which, Stone says, “comes down to convenience, suitability for our (ultimate) end, our finitude: Zweckmäßigkeit.” But this makes no sense. Zweckmäßigkeit means “suitability to [a] purpose.” It makes no sense to say that our “ultimate end” is “suitability for our ultimate end, which is suitability to a purpose.” What purpose? Carnap talks in §105 not only about means but also about ends; “our ultimate end” can’t be an infinite regress of instrumental values.
Finally, though, how does any of this fit with Stone’s first sentence, attributing a demand to Carnap that we overcome our “despair” in “faith”? First of all, what “despair” are we talking about? In the context of Stone’s paper, the reference is to Husserl’s failure to give unique, unequivocal meaning to his terms. More immediately, in the paragraph before this one, “despair” is really cowardice, unwillingness to face the sober truths (those inconvenient little facts Nietzsche talks about) that science conveys. For Carnap, this was no reason for “despair” but rather for giving up on certain intuitively plausible assumptions of traditional philosophy (more on this forthcoming). It seems obvious (to me, anyway) that the preface to the first edition of the Aufbau where Carnap mentions his “faith” in the future is characterized more by optimistic hope than by “despair.” (We may in retrospect find the vast hopes invested in the new tools of logic exaggerated, but if so that is our “despair” and not Carnap’s.) And how are we to understand “faith” here? Remember, this is in the context of a passage where Carnap explains that while irrationality is certainly not absent in science, the grounds for any scientific assertion must be “empirical-rational,” and that this is the aspect of science that he thinks philosophy should emulate. So is “faith” here (Carnap introduces the word by saying “this insight, or rather, to be more precise, this faith. . .”) likely to mean “irrational belief”? It is far more plausible, I think, to understand it as something like “to-some-degree inductively grounded hope”: In the past, scientific ideas, while at first condemned and proscribed, have gradually achieved authority not only within scientific circles but to some (increasing) degree, among the species at large. So it is reasonable to believe, and to hope, that the same will happen in the future as science becomes more comprehensive and comes to include parts of what used to be philosophy.
Note that I am not questioning Stone’s project of looking for symmetries between Heidegger’s and Carnap’s response to Husserl. But it would require an argument to extend that to a more substantive equivocation between Heidegger and Carnap, i.e. to extend the symmetry of response to one of doctrine, and claim that after all there is irrational faith on both sides. The traditional riposte to positivism for the past century or two has been that it relies ultimately on a different faith that is just as irrational as that of the doctrines it seeks to undermine. I think there is something to this, certainly as it applies to pre-Carnapian positivism, but so far, at least, I don’t see that Stone has got us out of the traditional rut.
UPDATE: Another post on a related subject, also touching on Stone’s paper.