Responsum: Negative, et ad mentem. The mens is that that the prescription of the Institutio Generalis Missalis Romani, no. 43, is intended, on one hand, to ensure within broad limits a certain uniformity of posture within the congregation for the various parts of the celebration of the Holy Mass, and on the other, to not regulate posture rigidly in such a way that those who wish to kneel or sit would no longer be free.