One Body: An Essay in Christian Sexual Ethics by Alexander Pruss (review)

One Body is a large, ambitious, and impressive defense of traditional Christian sexual ethics. Its argumentative core is personalist (though dependent on some biologically oriented Thomistic considerations), while its stylistic debts are to analytic philosophy (which so loves imaginative examples: expected but unintended sexual arousal outside of marriage must be permissible sometimes, since it might occur while “rescuing attractive naked people from a burning building” [356]). Like most defenses of traditional sexual morality, One Body depends on a central argument whose consequences are then carefully applied to a wide range of cases. Alexander Pruss’s argumentative tenacity (One Body “bristles” with arguments, as they say) is extraordinary, and One Body will become a standard text in sexual ethics. Here I will concentrate on his central philosophical argument, leaving to one side the many particular applications, as well as his interesting, though subordinate, discussions of Christian revelation and tradition.

Each particular form of love is distinguished by the type of union or consummation that fulfills it. Sexual union, the consummation of erotic love, is, in turn, best understood as an objective “one-body union” (91). This one-body union of two distinct persons is a “biological” or “organic” union and not a literal or metaphysical union. Such biological union “requires coordination and striving for a common goal” (102). These claims are so far fairly benign, and now we must ask, given a standard case of non-controversially unitive sexual activity, what it is about this activity that yields a union as one body and a consummation of erotic love? And what is the common goal movement toward which produces this one-body union? (114)

Pleasure cannot be the common goal of sexual activity, in part because it is neither necessary nor sufficient for union. Even if one or both persons are unable to feel sexual pleasure during intercourse (perhaps various nerve endings have been damaged), they still seem to be united as “one body”; adultery would be just as problematic despite an absence of pleasure. And if two people could experience sexual pleasure by means of the joint operation of some complicated machine, this would not entail a one-body union. But more importantly, “the most serious reason why striving for mutual pleasure is not what produces the union that romantic love seeks is that the conscious experience of pleasure does not, in itself, have an independent value” (118). Pruss follows Aristotle in arguing that pleasure “is enjoyment of an activity, and is given its form by the activity” (121). But “if sexual pleasure is an affective reflection of a deeper good, then surely it is the deeper good that is more appropriately seen as the goal of the unique striving, at least if the union to be produced is a deeper one—and romantic love seeks deep sexual union” (125). Sexual pleasure is good and should be present in full one-body sexual union, but its nature as pleasure points us to something deeper and more important, and so pleasure itself cannot be the distinctive unifying characteristic of unitive sexual activity.

The second possible cause and goal of one-body union is some higher-level purpose. The problem with higher-level goals is that the striving after these goals is not of itself “the striving that helps make two persons into one body” (128). “All of [these goals] set up the goal that is achieved by the mutual striving at a higher level than the biophysical. The goal in each case is something cosmic, spiritual, intellectual, volitional, and/or emotional. This does not make the union be a fleshly union as one body, since a single body is constituted by the striving of parts to achieve various goals at a biophysical level” (130). Not only is it often the case that a higher goal can be achieved in ways other than sexual union (meaning that the pursuit of this goal cannot specify one-body sexual union as...