to the first Critique (A5/B8):
The light dove, cleaving the air in her free flight, and feeling its resistance, might imagine that its flight would still be easier in empty space.Currence comments: "Talk about frictionless spinning in the void." This is of course a reference to McDowell's criticism of Davidson's "coherentism" in Mind and World. Interesting connection, and the image is certainly similar in the obvious way, but I'm actually put in mind of two other images which I think are more closely related than McDowell's to the point Kant is making here. (McDowell is accusing Davidson of succumbing to a dualism of reason and nature, but I don't think he takes him to do so because of this particular bird-brained inference, even if we can describe in similar terms the unfortunate dualistic result. For further thoughts on this matter see Daniel's post here, which just appeared while I was writing this.)
The first image is from Wittgenstein. The line of thought extends back several sections, so to see what he's after let's join in at §94 (I've altered the translation slightly):
"A proposition is a remarkable thing!" Here we have in a nutshell the subliming of our whole account of logic. The tendency to assume a pure intermediary between the propositional signs and the facts. Or even to try to purify, to sublime, the signs themselves. [...]The first quarter or so of Philosophical Investigations is often regarded as preliminary throat-clearing, in which the mature Wittgenstein criticizes his former self, clearing the rubble away before getting on to his real arguments, about rule-following, "private" language, aspect-seeing, and other topics in mind and language. But "clearing the rubble" (as in §118) is how Wittgenstein describes his entire project, not just its unavoidable preliminaries. These earlier sections are not mere preliminaries, but are instead the beating heart of the book. The later sections, while important, are where Wittgenstein unpacks what he has already said and applies it to particular cases (which are themselves carefully chosen to reinforce the earlier points about language – that is, they're not merely applications of a supposedly already established general principle).
In fact, Wittgenstein mentions his former self only rarely. Yet it is true that that philosopher comes in for some pointed criticism here. Putting aside, if we can, the vexed question of whether the rejected view is a) false or b) nonsensical (and the equally vexed question of how exactly the criticized author of the Tractatus would himself regard these words!), let's look at how Wittgenstein characterizes the "illusion" which tempts us here (§97):
[Thought's] essence, logic, presents an order, in fact the a priori order of the world: that is, the order of possibilities, which must be common to both world and thought. But this order, it seems, must be utterly simple. It is prior to all experience, must run through all experience; no empirical cloudiness or uncertainty can be allowed to affect it.——It must rather be of the purest crystal. But this crystal does not appear as an abstraction; but as something concrete, indeed, as the most concrete, as it were the hardest thing there is (Tractatus Logico-Philosophicus No. 5.5563).Just so you don't have to look it up, 5.5563 reads:
In fact, all the propositions of our everyday language, just as they stand, are in perfect logical order.—That utterly simple thing, which we have to formulate here, is not a likeness of the truth, but the truth itself in its entirety.Note that the first sentence there is something that the later Wittgenstein as well is concerned to stress [e.g. PI §98] – but he draws from it a quite different moral: not that in order to account for this everyday order we must posit [what he later calls, farther on in PI §97] a single ideal "super-order," but instead that when we are "dazzled by the ideal" in this way, we "therefore fail to see the actual [i.e. varied] use of the word [e.g.] "game" correctly." (§100).
(Our problems are not abstract, but perhaps the most concrete that there are.)
This sets up (as I've bolded below) the famous image I wanted to mention as an interesting comparison to Kant's, in §107:
The more narrowly we examine actual language [searching for the elusive ideal order], the sharper becomes the conflict between it and our requirement. (For the crystalline purity of logic was, of course, not a result of investigation: it was a requirement [impressed upon us, Wittgenstein believes, by our having "predicate[d] of the thing what lies in the method of representation" (§104)].) The conflict becomes intolerable; the requirement is now in danger of becoming empty.—We have got onto slippery ice where there is no friction and so in a certain sense the conditions are ideal, but also, just because of that, we are unable to walk. We want to walk: so we need friction. Back to the rough ground!(We've all seen that last injunction many times, but rarely, I think, with its proper force.) In any case, we might just as well say "We want to fly: so we need wind resistance. Back to the dense air!"
What I find particularly interesting here is that Wittgenstein and Kant strike upon such similar images in talking about what might seem to be rather different things. What this means, I take it, is that the error, the temptation, which they both aim to combat is so ingrained in our ways of talking and thinking that it manifests itself whenever we look to obtain a reflective perspective on them.
The second image returns us to a context which is (in one way anyway) more like Kant's than Wittgensein's. We find it in the "'Reason' in Philosophy" section of Nietzsche's Twilight of the Idols. Nietzsche has just condemned everybody from the Eleatics through (what was then) last Tuesday for rejecting the testimony of the senses as an unreliable guide to really real reality, and he's still not finished with his denunciations. His ultimate target here is the First Cause, but in context the particular gripe looks to me the same as Kant's and Wittgenstein's: he laments our instinctive urge to prioritize, reify, and detach the abstract and general and necessary from the concrete and specific and contingent. (Of course, on most interpretations we find some inconsistency in Kant on this point; but in his comments immediately following the line about the poor dove, Kant explicitly mentions that this is what happens when "Plato left the world of the senses, as setting too narrow limits to the understanding, and ventured out beyond it on the wings of the ideas, in the empty space of the pure understanding").
Anyway, here's Nietzsche:
The other idiosyncrasy of the philosophers is no less dangerous; it consists in confusing the last and the first. They place that which comes at the end—unfortunately! for it ought not to come at all!—namely, the "highest concepts," which means the most general, the emptiest concepts, the last smoke of evaporating reality, in the beginning, as the beginning. This again is nothing but their way of showing reverence: the higher may not grow out of the lower, may not have grown at all. [...]When we are concerned to grasp (only) the purest essence of concepts, we do not simply fail to do so (as if it simply eluded our clumsy grasp, like the "torn spider web" Wittgenstein has us trying to repair with our fingers in PI §106); indeed, even "success" in this endeavor, were we able to make sense of it at all, would merely capture, not reality at its highest, but its exact opposite: "the last smoke of evaporating reality." Here again, as in the other images, we see the (if you'll pardon the expression) essential perversity of the platonistic and/or Cartesian ideal – which is of course a theme on which Nietzsche plays many variations throughout his writings.