In Eisenstadt v. Baird, the Supreme Court considered a Massachusetts law that treats married and unmarried individuals differently with respect to access to contraceptives. Here is how Justice Brennan describes the law:

The statutory scheme distinguishes among three distinct classes of distributees – first, married persons may obtain contraceptives to prevent pregnancy, but only from doctors or druggists on prescription; second, single persons may not obtain contraceptives from anyone to prevent pregnancy; and, third, married or single persons may obtain contraceptives from anyone to prevent, not pregnancy, but the spread of disease.

It is the last category that confounds me every time I teach the case.  By definition, a contraceptive is designed to prevent pregnancy. Many contraceptives also serve the role of preventing the spread of disease–so long as it establishes some sort of physical barrier. In contrast, other contraceptives–such as the birth control pill–cannot halt the spread of diseases. How can something prevent disease, but not pregnancy? That is, if a product prevents skin-to-skin contact, or blocks the transmission of fluids, wouldn’t it also prevent pregnancy? (Granted, it is not 100%, but it provides some protection).

Today, vaccinations such as Gardasil can prevent someone from contracting HPV, and certain antiretrovirals can prevent the transmission of HIV. But I am fairly certain such products did not exist in 1972 when Eisenstadt v. Baird was decided.  Maybe they are talking about antibiotics that could treat various STIs, and thus prevent their transmission? But then how would that be also characterized as a “contraceptive.” I don’t know.

So I pose the question: What is a “contraceptives … to prevent, not pregnancy, but the spread of disease”? Here is the graphic of all FDA-approved contraceptives for you to choose from.

If the answer is indeed a null set, and no such products exist, then it would suggest the Massachusetts legislature was simply trying to prohibit all manner of contraceptive for unmarried people–a result that was consistent with Griswold, but was promptly dispatched by Eisenstadt.

Update: You ask, the internet answers. I think crowdsourcing has come up with the most likely explanation–the question was one of intent. Did the person intend to use the product to prevent pregnancy, or intend to use it to prevent the spread of disease.

@JoshMBlackman one might use condoms to prevent disease even if one was infertile (or gay)

— Irin Carmon (@irin) April 8, 2016

@JoshMBlackman If the latter, then they are the same contraceptives, just obtained for a different reason.

— Roger Ford (@rford) April 8, 2016

@JoshMBlackman I think the language refers to intention of prescriber and/or user, not function of product.

— Robert VerBruggen (@RAVerBruggen) April 8, 2016

@RandomlyBob offered some caselaw support:

@JoshMBlackman I suspect it’s referring to condoms specifically, and not what the device does, but what the intention of the buyer is.

— Robert Woolley (@RandomlyBob) April 8, 2016

@JoshMBlackman Commonwealth v. Baird, 355 Mass. 746 at 754, discussing whether conviction requires proof of illegal purpose of said device.

— Robert Woolley (@RandomlyBob) April 8, 2016

Here is the passage from the SJC’s opinion:

Even accepting the statute as constitutional in prohibiting distribution, there still must be considered whether there has been a violation in this respect. It is argued that the *754 act of giving away the device should have been, but was not, accompanied by an intention that the article be used for the prevention of conception. See Commonwealth v. Corbett, 307 Mass. 7, 29 N.E.2d 151 (1940), which construed G.L. c. 272, s 21, and states (12n.), ‘As has been shown, the words of the statute require proof of intended use for an illegal purpose, and are not satisfied by mere incidental result.’ The contention is developed that on the evidence the distributor’s intent could have been any of a variety of reasons, including inviting arrest in order to test the validity of the statute. But the judge made no findings on this point, and we are not able to do so. There is also nothing to show that unlawful use was intended by the recipient. See the Corbett case, supra, 10, 29 N.E.2d 151.

Com. v. Baird, 355 Mass. 746, 753-54, 247 N.E.2d 574, 579 (1969)

And @JoshACLU offers this textual hint that I missed:

@JoshMBlackman It says they “obtain contraception to prevent” not “obtain contraception that prevents.” “To” refers to reason for obtaining.

— Joshua Block (@JoshACLU) April 8, 2016

Brennan’s phrasing was inapt (what else is new), but he did convey the intent element, albeit obliquely. I’m glad I got this figured out.