From the first, because Schumann denies the erotic with a falling cadence at the end, comes the general statement that "the descending melodic impulse at a cadence is typical and is a central component of the tonal system" (329). "Typical" not "universal" -- Schachter never goes so far as explicitly to claim the latter for descending lines in cadences -- but nevertheless essential to "the tonal system," the latter, as we find out during the discussion of Brahms, being defined as Schenker construed it. Thus,
That descending melodic movement tends to create repose might be understood as reflecting our physical lives as creatures subject to the force of gravity. It takes effort to throw a ball into the air; it falls back to the ground by itself. Accordingly we might well imagine that musical descent suggests repose by analogy with physical motion…. (330). . . the ensemble of pitches conforms in part to the inner structure of a normal musical tone. . . . Musical motion toward the first partial -- " descending" motion -- leads to a fixed point of reference and thus tends to evoke a feeling of repose comparable to a move down through space. In the music of triadic tonality, this general attribute of downward motion is intensified by the fact that the triad is built from the bottom up. . . . In tonal music, the most stable positions of the triad are of course those where the root is grounded in the" earth" of the bass part. And in the melodic lines of tonal music, a descent from ^3, ^5, or ^8 to ^1 replicates in the horizontalized triad of the upper voice a move from an overtone . . . to the fundamental sound. (331)
Out of this recital of familiar notions comes the foregone conclusion that "for tonal music, the distinction between up and down is far from superficial, since moving down provides a more definitive closure."
David Lewin argues differently. Reacting to Susan McClary's charges about patriarchal containment of women's voices, he rejects an analogy between the spoken sentence and the sung phrase (and therefore a naturalized linkage between "coming to rest" and descending melodic movement): "Our musics are not 'natural phenomena,' like everyday speaking. All singing styles, in particular, are highly stylized in comparison to everyday speech" (275).
I would add that the notion of cadence-as-repose within a tension-relaxation model has no place in the singer's physical experience of performance -- tension in the body (diaphragm, lungs) rises to its top point before a phrase starts and is maintained till after the phrase is finished. One doesn't need to be a professional singer to experience that, either -- or a singer at all, since playing a wind instrument works essentially the same way.
Instead, Lewin associates patriarchy with priority to the bass (or fundamental), and from this it follows that "the transcendent musical voice must be a woman's voice" (271): "The female voice is typically acoustically free of what we conceive as a functional bass line—whether continuo or fundamental bass—and that is less typically true of the male voice" (274).
For Schachter, a certain set of historical practices in European tonal music may as well be universals ("fixed points of orientation [the tonic note, triadic roots]. . . important functional differences. . .the system itself"), but for Lewin they still have strong traces of cultural practices that can be interrogated. For Schachter, the difference between rising and falling melodic gestures offers wonderful expressive tensions in a balanced system; for Lewin, that balanced system may also be understood as a constraining cultural construct that can be "escaped" not just by the mad women of nineteenth-century opera but also by the transcendent female voice (pace McClary, Lewin counts Isolde and the soloist in Schoenberg's second string quartet and Erwartung among these).
However one reacts to Lewin's specific argument here, it is certainly well-established through historical narratives connected to neo-Riemannian theory that in the nineteenth century a harmonic model emerged that opposed symmetrical models to traditional "Earth-bound" metaphors. I also claim that whether through a Newtonian concept of gravity, the Romantic's exploitation of oppositions, or simply through a desire to escape from century-old, clichéd cadence figures, the opposition of rising and falling gestures was altered to contest (or to vitiate) the structural priority of descending cadence gestures.
References:
Lewin, David. 2006. Studies in Music with Text. New York: Oxford University Press.
Rings, Steven. 2006. Review of three books by David Lewin in new editions. Journal of Music Theory 50/1: 111-27.