OUR MEDIATRIX: Mary has a double right to this title. First because she is the means, the path, by which Christ was given and born to us. Bernard used a phrase which is difficult to translate because it contains an allusion to the biblical and patristic theme of the royal road, (the king’s highway in the Revised Standard Version): Virgo regia ipsa est via per quam Salvator advenit. The Virgin is the road by which the Savior came to us, but she is also the means, the path, by which we are to go to Christ. Here again Bernard uses a scriptural reminiscence: ‘Through you we have access to the Son, who through you came down to our misery’.
Mary is also mediatrix because she is the intermediary who powerfully intervenes on our behalf before her Son: potens est enim. The mediator’s role is to conciliate and reconcile. In the language of ancient roman law the mediator is the ‘go-between’ who tries to settle a dispute and bring about a reconciliation between two parties. In medieval law the word applied to someone who negotiated peace, or to the arbitrator in a lawsuit, or again, the man who stands as warrant, the privileged witness.
Jean Leclercq, Women and Saint Bernard of Clairvaux (1989)