In our western judicial system, inherited from Roman Law, it is consent, and consent alone, which creates marriage. It is only a small step from the idea that it is the exchange of consent which creates marriage to the idea of marriage as a contract. In the canonical doctrine of the Code of 1917, the contractual nature of marriage was simply taken for granted. Yet, this contract was sui generis because there can be no mutual recision once the parties contractually agree by their consent. In addition, the marriage contract has special characteristics: it is necessary for the human race, it is of itself sacred, it deeply concerns the public order, it is restricted to members of the opposite sex and to the number (two) of contractants, and it is bilateral and reciprocal. These conditions specify the contract.

In the 1917 Code of Canon Law, it was consent which gave rise to the marriage contract. This consent had to be manifested by persons who are capable of consent: jure habiles. This code did not speak of a specific capability relative to marriage. The reality of capability, however, was known because it arose from natural law. For Cardinal Gasparri, author of the 1917 Code, someone born blind, deaf, and dumb is an idiot who is assimilated to a child and therefore is incapable of contracting marriage.