Since our Apostolic Administrator is more catholic than the Pope, the annual archdiocesan Pentecost Mass for New Movements and Ecclesial Communities has for several years included an invitation to those of us in Old Movements like the Dominican Third Order and the Secular Franciscan Order.
This year, there was a reception beforehand, featuring presentations from the various new movements and communities. (The old orders seem to be on the invitation list but not on the Archdiocesan Council on Ecclesial Communities and New Movements.)
I was struck by both the new movements' similarity to and their difference from the Dominican Third Order as I understand it ("as I understand it" because my understanding of the Dominican Third Order isn't necessarily the only or best one).
The similarity is straightforward enough; you might say the formal causes of all these associations are variations on Christ's call to perfection and evangelization.
The difference, though, is a subtler matter, harder to state without having to take most of it right back, and I probably shouldn't even try. I'll just say that the terms "movement" and "order," calling attention to activity and structure respectively, do seem to reflect something of the difference. Even, in a sense, the difference between "new" (as it connotes energy and activity) and "old" (as it connotes "stable" and "enduring").
Also, "movement" might suggest "mass movement," and I certainly got the sense that a lot of the new movements see themselves as something everyone could, in principle, join. Dominicans are very aware of the fact that most Catholics would not enjoy being Dominicans, and we have no real degrees of involvement or association.
True, for purposes of chapter governance, there's a distinction between the various stages of formation and the commitments that have been made to date, but basically you're either on track for final, lifelong profession, or you're not a Third Order Dominican. (Many congregations of Dominican sisters do have associates, and there are a variety of confraternities whose members share in the spiritual works of the Dominican Order, but these aren't tied directly to the Third Order.)