The Church's teaching on marriage has evolved over the centuries. Crucial distinctions have been made over time, such as the distinction between the validity and indissolubility of marriage, and the conditions for these two aspects have been defined. The link between indissolubility and the couple's first sexual intercourse after marriage stems from the marriage contract, which includes the right to start a family. To protect the indissolubility of the marriage contract, it was defined in modern times that a marriage contract between Catholics is automatically a sacrament. This lecture will examine whether a further development of the Church's teaching on marriage is conceivable, taking into account historical developments.