Beginning with an analysis of an early satire of Kant's doctrine of marital law, this essay draws on Walter Benjamin's condensed exposition of this doctrine in order to ask whether Kant's notoriously unsentimental representation of marriage is, in fact, from the perspective of his own idea of law, overly sentimental. Whereas Kant ridicules the idea of a "law of war" in his program for perpetual peace, he accepts the possibility of legally sanctioned intercourse, in which people use others and themselves. Between marital law and martial law lies maritime law, which concerns a surface that can be used but not mastered.