Like a used car, must a groom take his bride "as is" – with no warranty implied as to the woman's chastity?

That was the question at the heart of a legal case that recently worked its way through the French courts.

The drama began on a Muslim couple's wedding night. Apparently, the bride wasn't the virgin the groom thought she was. He immediately brought suit to annul the marriage on the grounds that his wife's virginity was an essential condition of the marriage. French contract law states that if one of the parties to a contract is mistaken as to some essential element, then the contract is void.

The question was whether the woman's virginity was an essential element of the marriage contract. If it was, then the contract could be annulled. If it was not, then the couple was validly married.

As neither party objected, the trial judge saw no harm in granting the annulment. He failed to foresee the media storm that would ensue. Prominent members of the French government, including the dynamic minister of justice, Rachida Dati, were outraged. She ordered the government to intervene and appeal the decision.

French law permits the government to become a party to any case in which French public policy is at issue. A woman's right to choose her first lover suddenly became a matter of public policy.

The decision of the trial judge quickly reached the appeals court, which reversed the judgment. At the appeals court, the husband changed his argument, saying that although he had hoped for a virgin wife, her chastity was not indispensable. It was her integrity that mattered. He claimed she lied to him and that truthfulness was an essential condition to a marriage. Mutual confidence and sincerity were, he argued, essential conditions of matrimony. Her deception concerning her virginity meant that he had not knowingly consented to the marriage.

His wife told a different story. She denied deceiving her future husband about her past. The subject of her virginity, she said, had never come up. Still, she agreed to an annulment because her husband lacked the intent to show her the respect required by the marriage vows, and that this was an essential condition to the marriage.

The government argued that the wife's virginity was not an essential condition because her unchaste past has no effect on married life. The judges agreed. Even if she had lied, they said, it did not matter, as a woman's lies about her past love affairs are not matters essential to her married life. In short, a woman's past is her own.

The court's legal analysis was one of "let the buyer beware," as though the groom were claiming to have purchased damaged goods. His mistaken belief about his bride's virginity could not, the court said, nullify his purchase. As a 19th century English judge put it, "on the sale of a specific article, unless there be a warranty making it part of the bargain that it possesses some particular quality, the purchaser must take the article he has bought, though it does not possess that quality." French law now holds that a groom receives no warranty as to his bride's chastity.

This case followed an equally dramatic one last year in which the French Supreme Court denied citizenship to a Moroccan woman because of the clothes she wore. In the eyes of the judges, her choice of a burqa and symbolized inferiority. (I am representing her appeal to the European Court of Human Rights.)

What conclusions can be drawn from these cases? They do not involve traditional arguments of equal pay, equal access, or discrimination. They go beyond mere legal equality to show concern for a woman's status in society. Yet the concern comes at the cost of imposing values not accepted by a portion of the French population. It is no coincidence that the parties to both cases were Muslims. Denying citizenship to a Muslim woman on the basis of the clothes she wears is at best a doubtful use of state power. The appellate court's limpid edict that a woman's past has no impact on her married life tries to impose a factual reality by a legal fiction. What does seem clear is that the Muslim presence in France is having an important impact on the development of French law.

• Ronald Sokol is a lawyer in Aix-en-Provence who practices across France. He taught at the University of Virginia Law School and is the author of "Justice after Darwin" and other books and articles.