Catholic sacramental theology teaches that a specific intention is not necessary. Only a deliberate contrary intention invalidates a sacrament. Most people, Catholics especially, who marry for the first time will initially intend to stay together for the rest of their lives and this is sufficient for a valid marriage. A marriage is always presumed to be valid unless it can be proved otherwise and that is the purpose of the tribunal. Even then the judgement is only conditional depending upon the truthfulness of the spouses and the witnesses.