Check out the whole thing over on Adoremus.org, which preserves a lot of rare and largely forgotten documents. (For example, for all of you traddy priests out there, when some dear soul tells you that your maniple is no longer permitted, you can send him over to Adoremus where he may read in Tres abhinc annos that it is only "no longer required." But I digress.)
Religiosorum Institutio is fascinating to me on a number of levels. Sometimes I think that those of us who grew up after the Council--and who perhaps seek to retrieve religious life from some of its twentieth century wanderings--can get this idea that everything was stable up until the time of the post-conciliar reforms, or worse, that everything was just fine until the reform wrecked everything. This document, among many others, shows that there were deep shifts going on before the time of the Council and its subsequent reforms. Religious life in particular was changing along with the world around it; how vocations came about was shifting along with the questions of the religious themselves.
The document is especially concerned with the responsible pastoral care of vocations and the selection of those who are admitted to clerical institutes in particular. Some parts of it are quite sad, such as this section on those who stay in religious life because they don't know what else to do:
At times such candidates, on the verge of Sacred Orders or perpetual profession and somewhat mature in age, finding themselves without academic degrees and untrained in any art or liberal profession, were afraid to leave the religious life, feeling deep down in their hearts that if they returned to the world, they could not make an upright living unless by manual labor, or would be obliged to make difficult and uncertain efforts to acquire a liberal profession. Therefore they regarded the decision to continue in the religious clerical life as a lesser evil.
(By "liberal profession" we may presume that the document means a career derived from a liberal education.)
Other sections strike prophetically at the condition of religious life, even fifty years later:
Lastly, not infrequently there is adduced as a cause the loss of the religious spirit either because, under the insidious impact of present-day naturalism, these priests become incapable of discipline and religious observance, or because, living in religious houses an indolent and unproductive life, deceived by the desire of life outside and ill-regulated pseudo-apostolic activism and neglecting the interior life, they fall victims to dangers of all kinds, which they do not avoid and do not even recognize.
Make of the document what you will, but it's certainly interesting not only as a glimpse into concerns just prior to the Council, but even on its own and in its wisdom for our own time.