避妊史における江戸時代の謎
A Japanese Puzzle in the History of Contraception
ファビアン・ドリクセラ（イェール大学）
Fabian Drixler (Yale University)
fabian.drixler@yale.edu
This paper concerns the following puzzle: why is there so little evidence that married couples in
Tokugawa Japan practiced contraception?
In parts of Tokugawa Japan, married couples practiced rigorous family limitation. From a variety ofdescriptive sources as well as demographic analyses, it is clear that this was achieved throughwidespread resort to infanticide and abortion. In the Deep East (the North Kantō and South Ōu),about 40 to 50 percent of children were aborted or killed at birth during the 18th century, according to
my own simulation model analysis.1
At the same time, effective contraceptive methods were known in at least some quarters of Japanesesociety.
1) The basic physiology of conception, including the role of semen, was widely understood.
2) Niffon no cotōbani yô confession, a record of confessions that Japanese Catholics gave to
missionaries in various parts of Western Japan in the 1610s, contains instances offemale-initiated as well as male-initiated contraception, and describes them in terms thatsuggest either coitus interruptus or a barrier method. One of these cases is a poor married
woman with six children trying to avoid further pregnancies.
3) Prostitutes used tsumegami pessaries throughout the Tokugawa period. Evidence for thispractice includes instructions in a manual (1678) and 18th-century senryū verses.
4) Condoms are mentioned by 1827; though they remained rare before the 20th century, thebasic principle of their operation could have been copied had there been more demand.
5) In addition, various other methods of questionable efficacy existed. Tsuitachigan(mercury-containing pills) were widely advertised in the major cities; kabutogata were soldas sex toys in specialized stores;
6) Unlike in pre-Transition Europe, there were no major moral or religious obstacles to the useof contraception of the spread of contraceptive knowledge.
Nevertheless, it appears that by the 18th century, contraception was not widely practiced outside
prostitution:
1) The few Edo-period scholars who mention contraceptives in their writings warn readers of theirextreme dangers.
1Fabian Drixler, “Conjuring the Ghosts of Missing Children: A Monte Carlo Simulation of Reproductive Restraint in Tokugawa
Japan,” Demography 52 (2015).

2) Edo-period scholars who wrote about the desire to avoid more children portrayed numerous
pregnancies as the inevitable consequence of early marriage.
3) Kōshinmachi wakes were justified in part by the need to avoid conceptions on unlucky nights.
4) Scores of men wrote about the problem of depopulation, especially in Eastern Japan, as caused bypeople not raising enough children; but none mentioned contraception in these texts. Given the manyfine-grained analyses of infanticide that men of the Edo-period produced, it would be strange ifpervasive contraception eluded comment in the context of depopulation had they believed that it
played an important role.
5) If contraception was widely employed in the 18th century, it is difficult to explain why thatknowledge was lost in the 19th and early 20th centuries, to be replaced with high fertility and an arrayof magical practices that folklorists recorded in the 1930s.
Possible interpretations:1) Have I been looking in the wrong places for evidence of contraception among couples?
2) Did the medical warnings against contraception scare couples?
3) Did husbands disregard their wives’ wishes for contraception, since for men, infanticide andabortion worked just as well? This could explain why we have no evidence for a wide adoptionof coitus interruptus, which relies on the initiative and discipline of the husband. But thisinterpretation assumes that women had no power, and that husbands were indifferent to thedanger of losing their wives in childbirth or a botched abortion.
4) Did knowledge of contraception not spread from prostitutes to the population at large? But
prostitutes were numerous, even in the countryside, and did not only service travelers but also
nearby villagers.
5) Was marital sex a matter of snatching opportunities as they arose, leaving no time forpreparations like tsumegami? But tsumegami did not require special materials and could
probably be chewed, folded, and inserted in a matter of seconds.
6) Did the association of tsumegami with prostitution make them unacceptable for marriedwomen? This may have prevented the spread of knowledge, or actually driven contraception outof a context where it had once prevailed. But the stigma of prostitution may not have been sogreat. Women living in family contexts at least sometimes imitated the hairstyles and dress ofprostitutes.
7) This leaves one other possibility: that married couples preferred infanticide, and perhaps alsoabortion, to contraception. Infanticide permitted the selection of the most promising children.
And perhaps pregnancies, for all their obvious disadvantages, were important for married
women’s identity and social standing, since they were evidence of their continued fecundity.
While the puzzle cannot be solved here, the balance of the evidence suggests a very different
sensibility from our own. In other words, other goals – perhaps sexual propriety, or a wife’s status asa fertile woman, or the desire to select the most promising children – were more important to many
people in the 18th and 19th centuries than the life of a child or the safety and comfort of its mother.