moted with great notoriety some sixtynyears ago. Bertrand Russell’s Marriagenand Morals, which Posner frequentlyncites, devotes a chapter to it, but Posnernhas apparently not taken notice.nThe type of marriage that has prevailednin the Western world for nearlyntwo thousand years is, according to Posner,ndue for replacement. Contemporarynwomen have entered the job marketnin large numbers and their financial dependencynon men has lessened. To Posner,nthis development portends the declinenof lifelong marriage. Cohabitationnfor limited periods will replace traditionalnmarriage, a trend that will proceednall the faster as developments inntechnology detach sex from biologicalnreproduction. Posner looks to the liberalnsexual morality of Sweden as the wavenof the future, at least for the West. (Hendevotes only a few pages to non-Westernnsocieties.)nPosner’s speculations are beset by annumber of problems. Of each of hisnstages, he asks: what economic functionsndoes marriage play in society? But tondescribe a function does not suffice for ancausal explanation, as Ernest Nagel longnago showed in a classic paper. Posnernneeds to demonstrate how the actionsnof individuals lead to the spread of thencustoms he describes. He devotes all ofnone paragraph to this key difficulty; thenimplausible “Darwinian” mechanism henrefers to requires primitive tribesmen tonpossess a sophisticated knowledge ofneconomics and anatomy.nPosner thinks that a great advantagenof his theory over “moralistic” explanationsnof sex is that it generates testablenhypotheses, e.g., “black men commitnfewer heterosexual rapes than whitenmen, after allowance is made for othernvariables that explain differences inncrime rates. . . .” While this particularnstatement “is not supported” by the data,nthe ever-ingenious Posner finds comfortnin the fact that although “the coefficientnof the nonwhite variable isnpositive for rape … [it is] much smallernin the case of rape than is the case ofnany other crime against the person.” Innother words, though the hypothesis isnwrong, it might have been even morenerroneous. Thus the theory is vindicated.nAlthough one can only be impressednby Posner’s vast erudition, albeit gatherednwith the help of 11 research assistants,nhe makes a number of questionablenclaims. For instance, he states that.n”Textual silences can be pregnant. R’omnthe fact that the Ten Commandmentsndo not forbid incest we should not infernthat the ancient Jews condoned thenpractice. …” He evidently has forgottennthat the Old Testament contains detailednregulations forbidding incest. Andnwhy does he think that the “disapprovalnof male adultery” began with Christianity?nAlthough by definition in the OldnTestament adultery can occur only withna married woman, both persons involvednare subject to the death penalty. As ansource for the Roman Catholic positionnon transsexual operations, he cites anpamphlet by an Anglican theologian.nSome Catholic theologians, Posner quitencorrectly thinks, are not completely hostilento contraception. But one of his twonexamples is Germain Crisez, a leadingnopponent of contraception who has writtenna book attacking it, and it is falsenthat David Popenoe, the foremost sociologistnof the Swedish family, found nonill results from Sweden’s family structurenexcept a rise in juvenile delinquency.nIf the book consisted only of Posner’sndescriptive theory of sex, it might be ratedninformative, though overly speculativenand careless. Unfortunately, a substantialnpart of the work consists ofnPosner’s venture into moral theory, andnhere his skill at argument deserts him.nHe discovers an internal tension innthe position of most critics of abortion.n”Suppose the mother has a 10 percentnchance of dying unless she has an abortion.nA majority of supporters of thenright-to-life movement would thinknabortion permissible in these circumstances.nThe implication is that a mothernis worth ten fetuses”—a contradictionnof their professed belief that the lifenof the fetus equals in value that of thenmother. Further, since a mother isnworth no more than a child, the lattern”is also worth ten fetuses. And this, Inclaim, is what right-to-lifers are committednto believing if they want their beliefsnto be consistent.” Not at all: a viewnregarding the permissibility of abortionnneed not be based in any way on a comparisonnof the value of different lives.nPosner seems incapable of grasping anmoral theory that, unlike his own utilitarianism,njudges acts by other criterianthan maximizing value.nIn his discussion of pornography, Posnernonce more puts logic to work: “Thenfeminists fear that pornography causesnrape; [Irving] Kristol that it causes thennnsubstitution of masturbation for intercourse.nSince rape is a form of intercourse,nKristol must believe that pornographynreduces the incidence of rape;nwhile feminists must believe that it reducesnthe incidence of masturbation.”nAn analogous “argument” will make thenfallacy clear. Television and books arenpartial substitutes for each other. Therefore,nan increase in the sale of calculusntextbooks will decrease the number ofnviewers of Sesame Street.nRape gives Posner more than a littlentrouble. It is not intrinsically wrong: thenview that certain acts are immoral independentnof consequences rests on religiousnbeliefs that Posner thinks outmoded.nAlthough most “Westernnintellectuals” have given up belief innGod, many continue to think that humannbeings are “not just animals endowednwith large brains but beings of anspecial worth and dignity, endowed withna moral sense and entitled to respectfulntreatment by our fellow men.” This isnidle superstition: it generates no testablenpropositions. Away with such nonsense!nWhy then is rape wrong? What if anrapist derives more satisfaction from hisnassault than his victim suffers injury?nWould a utilitarian then favor it? Posner’snmoral slide rule gives us the answer:n”licensing utility monsters such asnBluebeard or de Sade to rape would notnreally be utility-maximizing, if only becausenof the fear it would generate innthe community as a whole and the expensenof the self-protective measuresnthat this fear would incite.” Were Posnernnot an influential federal judgenwhose views help form the law, this imitationnof Mr. Gradgrind would benlaughable.nWhat is the upshot of Posner’s longninquiry? Fie vigorously opposes effortsnto promote the traditional family. Resistancento the Swedish Utopia that liesnahead comes from “social conservatives,nwho dislike change.” These troglodytesnlack the trust in the free market of thenfollowers of John Stuart Mill. Thatnmany of these “social conservatives” supportnthe free market to a far greater extentnthan Mill seems not to have occurrednto him.nPosner himself hardly qualifies as anchampion of the free market. He favorsngovernmental subsidies of sexual educationnand contraceptive advice, evennthough his own analysis of the consequencesnof abortion, homosexuals in thenmilitary, etc., lends only “equivocal sup-nOCTOBER 1992/37n