To give oneself over to the object is tantamount to doing justice to its qualitative aspects. In keeping with the quantifying tendencies of all science since Descartes, scientific objectification tends to black out qualities, transforming them into measurable determinations. Rationality itself is increasingly identified, more mathematico, with the capacity for quantification. This notion accounts with great accuracy for the primacy of a triumphal natural science, and yet has precious little to do with the concept of reason as such. It is blinded, not least because, having charged itself with the task of rational thought, it seals itself off against the qualitative aspects of the object. Reason is not merely συναγωγή, synagoge, an ascent from scattered phenomena to their basic concept or generic name. As much as this other, it demands the ability to differentiate. Without this, the synthetic function of thought, abstractive unification, would not be possible: To gather like terms necessarily means to separate them from the unlike. But this is a qualitative matter; thought that does not think this is itself already diluted, cut, and at odds with itself. At the origins of European rationalism, Plato, who was the first to institute mathematics as a methodological model, still gave ample expression to the qualitative aspect of reason, and he did this by placing διαίρεσις, diaeresis, alongside and on an equal footing with συναγωγή, synagoge. This amounts to the imperative that consciousness, bearing in mind the distinction, at once Socratic and sophistic, between physei and thesei, shall hold close to the nature of things; that, it shall not deal with them in an arbitrary manner. Qualitative discrimination is thereby not only incorporated into the Platonic dialectic, into Plato’s theory of thinking, but is also construed as a corrective to the violence of quantification unbound. A simile from the Phaedrus dispels any doubt. In it one finds balanced against each other non-violence and a thought that at once injures and makes ready. Reversing the conceptual motion of synthesis, it says that, when dissecting something into subspecies, one must “be able to cut up each kind … along its natural joints”; one must “try not to splinter any part, as a bad butcher might do.” [Nehamas edition] In all quantification, there survives, as substrate of whatever is to be quantified, this qualitative aspect, which, as Plato admonishes us, is not to be shattered, lest reason, by dealing damage to the object it is meant to acquire, flip over into unreason. Of a piece with reason’s operation—as the element of antidote, so to speak, in its second reflection—is quality, which the parochial first reflection misappropriated from science in the philosophy that is at once submissive and alien to it. There is no quantified insight that does not receive its meaning, its very point, by being translated back into qualitative terms. The knowledge-goals of statistics itself are qualitative; quantification is only the means thereunto. To absolutize reason’s tendency to quantify is to fall in line with the former’s want of self-reflection. Such self-reflection is served by insisting on the qualitative, which insistence does not augur irrationality. At a later date, it was only Hegel who seemed aware of this without inclining towards the retrospective and romantic, albeit at a time when the supremacy of quantification was not nearly as uncontested as it is today. He might, it is true, agree with the tradition of science that “the truth of quality itself is quantity.” But in the “System of Philosophy,” [the shorter Logic, Zusatz to 90] he recognizes quantity as “no longer immediately identical with Being, but a mode indifferent and external to it.” [Wallace translation] According to the greater Logic, quantity is “itself a quality.” This latter retains its relevance within the quantitative; and the quantum reverts back to quality.
THEODOR ADORNO, NEGATIVE DIALEKTIK (1966), pp. 53-54