The Council of Trent called for a restoration of a Permanent Diaconate that would be open also to men who were already married. The Council did not intend to "reduce" the diaconate to a kind of "lay order"--there is no ontological impediment to Holy Orders if a man is married, only a disciplinary one. Indeed, married priests (though not bishops) are not uncommon in the Eastern Churches, and the Latin Rite also has married priests in some areas.
As it happens this desire of the Council was not immediately met. It was not until the Second Vatican Council renewed the call for a restoration of the Permanent Diaconate that this desire of Trent was finally fulfilled. Even today, however, fifty years after the Council, not every diocese has the Permanent Diaconate. My own diocese, Steubenville, only instituted the Permanent Diaconate in 2009.
Now Archbishop Kieran O'Reilly of Cashel and Emly, Ireland, has set up a commission to investigate the Permanent Diaconate for his archdiocese. A group of Irish priests calling themselves the Association of Catholic Priests has objected to this move on the grounds that it is "insensitive, disrespectful of women, and counter-productive". They wrote, in part,
Currently the Church confines the lay diaconate to men, even though Pope Francis has a commission working on the history of women deacons in the early church, with a view to possibly opening the diaconate to women also.These references to a "lay diaconate" and to the "opening" of the diaconate to women reveal that the Association does not really know what it is talking about. The diaconate is part of Holy Orders, it is not an association of laymen. And because of the unity of Holy Orders, only men can be ordained to the diaconate. What Pope Francis is investigating is not whether women may be ordained, either to the diaconate or to anything else, but whether there isn't a form of diaconal service to which women may be admitted.
The women who are named as "deaconesses" in the earliest documents regarding the diaconate were not ordained with the laying on of hands, the mark of Holy Orders. Rather, they were serving the Church in a form of ministry that is, in fact, not only open to, but already conferred upon all Baptized persons. The Greek word διακονία simply means "service", and a person who is engaged in service to the Church is, by definition, a διάκονος, a "servant" of Christ's church. All men and women who have been baptized are called to serve the Church, but we no longer use the word "deacon" to describe their service since the term has come to be bound up with Holy Orders and it would be confusing to use the same word to refer both to Ordained and to non-Ordained forms of ministry.
But in the sense that Baptized persons are indeed called to a special form of service there is, after all, a kind of "lay diaconate"--just not the kind that the Association of Catholic Priests thinks there is.