I am, perhaps, taking just a phrase from each of these two posts and adding to them a reflection not intended by their original authors.
First, tigerish waters, who some time ago posted on the Instrumentum Laboris for the forthcoming Synod of Bishops on the family. Read her post before reading my comments that follow.
I think the most interesting question tigerish waters asks is that of whether the (biological) family as a unit receives a mission or whether it is the individuals, particularly but not exclusively the parents, within such a family unit who receive a mission. Clearly such a mission, as a vocation received from the Lord, exists in the order of grace, and is certainly there for a Christian married couple. It might not, however, be completely absent from a "natural" marriage between non-believers who live a family life rooted in a genuine "good will".
Every family, within the wider context of a calling of the couple to a vocation that they share in common with other couples, is called to live that vocation in circumstances that are unique to them; and these circumstances give a specificity to their living of that vocation. tigerish waters question prompts me to wonder whether the Synod Fathers should try to teach in a universal way of a mission of the family, ad extra. For some families, the specificity of the circumstances of the couple might make that appropriate - families, for example, who through an engagement with an ecclesial movement are sent to a new part of the world as missionary families. But for others, the notion that they should be "active in the parish" rather overrides a primacy of a mission of the couple towards their own family - if they are to fulfil that mission, they simply do not have the time to be a parish catechist. The sense in which it is possible to speak universally of a mission of the family in society needs a careful relation to the mission of individuals in the family.
Secondly, Fr Christopher Jamison, who writing on A great Catholic marriage revolution, identifies a language of "discerning a vocation to marriage" as indicating a significant change in the way the Church speaks about marriage. Again, read his post before continuing.
Fr Jamison is referring, I think, to an action of discernment on the part of the couple themselves as to whether or not they have a calling to marriage. Of its very nature, this discernment needs to be a shared discernment of the couple ..... so it must radically challenge any culture of a "proposal" on the part of one party and a "yes" on the part of the other. It requires a shared conversation.
As far as the discernment of other vocations in the Church is concerned, those who hold office in the Church - Bishops, religious superiors or a vote in chapter - play a definitive part. How far is something similar appropriate to the discernment of a vocation to marriage? There seems to me some implication of this at least in the use of the language of "discernment" that Fr Jamison sees as marking a change in the way the Church is coming to speak about marriage. If a couple approach a parish priest asking for a marriage in Church, but clearly have no understanding of Catholic teaching about the nature of a sacramental marriage .... does not the parish priest have a part to play in helping the couple to discern the vocation to a sacramental marriage, and whether or not that is the vocation that they have in their relationship? And is this part to be played in discerning the vocation of a couple one that can be "delegated" from the priest to the marriage preparation course provided by such as Marriage Care? It will be interesting to see where the Synod Fathers get to in reflecting on the part that is played by "office" (in the Balthasarian sense) in the discernment of vocations to marriage in the Church.