Thanks for the question. The first statement is entirely incorrect. Remember, a diocesan hermit does not make her vows to a particular bishop. She makes them to God in the bishop's hands. In so doing she becomes a hermit of the Diocese of x --- rather like diocesan priests are priests not just in a particular diocese but priests of a specific diocese. When a new bishop comes to a diocese a diocesan hermit in perpetual vows does not need to worry about relocating at all. The new bishop assumes pastoral/episcopal responsibility for the whole diocese and that includes any and all diocesan hermits. My own profession, for instance, is perpetual and canonical. I have been given a particular "standing in law" and my vocation is governed on the diocesan level (though recognized by the universal Church), no matter who is or becomes the bishop. When I speak of the rights and obligations of canonical standing, freedom from arbitrary situations like the one described in your quotation are part of the "rights" involved.
Nothing undoes this canonical standing except a formal (i,e., canonical) act of dispensation. There is nothing hypothetical about this situation (nor that of Sister Rachel Denton, Er Dio). There have been four bishops since I have been professed and consecrated (one was interim). This means I have had three different bishops as legitimate superiors (the Vicar for Religious served during the interim). There was never the least question about my ceasing to be a diocesan hermit due to these shifts. Now, it may be true that a bishop sympathetic to the vocation does a better job in relation to his pastoral role with a diocesan hermit than one who is not open to using c 603, but the hermit is perpetually professed and a new bishop becomes the new superior whether he agrees with the implementation of c 603 or not.
New Bishops in Cases of Temporary Profession:
If, on the other hand, a diocesan hermit is only temporary professed under c 603 (and therefore, also not yet solemnly consecrated), and a new bishop is installed who does not want to implement c 603, there is a chance he could simply allow those vows to lapse and refuse to admit the hermit to perpetual profession. I have never heard of such a case. My sense is that, instead, the bishop would recognize the time and significant process (and commitment!) that is already spent and underway; he would discern in good faith this particular vocation even if he had already decided not to admit anyone else to profession under c 603 in the foreseeable future. Since he can easily delegate someone to be the hermit's superior and act as such for him, such a situation would not be onerous. Moreover (at least this tends to be true in larger dioceses), since bishops rarely deal with hermits until the Vicars for Religious are ready to recommend profession, the c 603 vocations are, again, not a burdensome matter for bishops.
After all, when one is temporary professed there have to be really good reasons for not admitting her to perpetual profession and consecration. A bishop can honestly discern reasons not to admit to perpetual profession, of course, but these will be done in good faith and not merely because of personal bias. (When one makes temporary vows, personally speaking, one is still disposing of one's life entirely; one is giving oneself to God and his People without limits, despite the temporary nature of the vow itself. This capacity is necessary if one is to be admitted to vows at all, even when the vow itself is temporary.) Remember too, others are and have also been involved in the process of discernment over a period of years. We are dealing with Divine vocations to the consecrated state and, generally speaking, bishops will not act whimsically.
Moving in Cases of Medical Necessity:
In medical situations like of those like Sister Rachel Denton in the UK, one would need to know the whole situation to say how inevitable the outlined solution is.This is because what is also true is that when one needs to relocate because of medical needs, the situation can be temporary or permanent. If it is a temporary situation and the hermit is perpetually professed, my sense is the hermit's bishop would speak to the bishop in the new locale and assure the hermit's ability to continue to live her public profession with the assistance of the new bishop --- much as when a priest is moved temporarily and granted temporary faculties. A hermit's diocese will, among other things, assure the hermit is professed and in good standing.
It is only when the relocation is a permanent one that the new bishop must accept the hermit's vows and assume full responsibility for such a vocation in his diocese. In the case of medical need I think it would be unusual for a bishop to refuse to accept the hermit's vows. His acceptance of this hermit in this situation would not need to mean a change in diocesan policy if the bishop was otherwise unwilling to implement c 603. However, if the bishop refuses and one moves permanently to this diocese anyway, then one's vows cease to be binding due to a material change in the circumstances under which they are valid. The original diocese may dispense the vows or otherwise declare the material change renders the vows invalid. (I don't know if they can or prudently need to do both.) What is clear is that in such a situation, the hermit leaves the consecrated state and returns to the lay state whether or not she continues to live as a hermit.
If, on the other hand, the vows are temporary, several different things can happen. Hopefully the medical treatment will allow the hermit to return to her diocese and truly live eremitical life in time to make perpetual profession. If not, both the hermit and the home diocese will need to decide what to do. So long as adequate supervision and regular spiritual direction can be maintained, renewing temporary vows while on "medical leave" of some sort is a possibility. Expediting perpetual vows is also possible (and most charitable) in some cases. Approaching the new diocese for admission to profession (whether temporary or perpetual) is another option so long as one can live one's Rule. Canon 603 is no longer an untried and entirely novel vocation. We now have examples of well-lived and edifying eremitical lives, rare though this vocation will always be. As a result, once a hermit has been professed under c 603 people will ordinarily work to discern the best thing for the hermit and for this canonical vocation itself.
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