Concerning the exhortation to be addressed many at once, that It may so aid the virtues of each among them that vices contrary to such virtues may not grow up through it.
These are the things that a Bishop of souls should observe in the diversity of his preaching, that he may solicitously oppose suitable medicines to the diseases of his several hearers. But, whereas it is a matter of great anxiety, in exhorting individuals, to be of service to them according to their individual needs, since it is a very difficult thing to instruct each person in what concerns himself, dealing out due consideration to each case, it is yet far more difficult to admonish innumerable hearers labouring under various passions at one and the same time with one common exhortation. For in this case the speech is to be tempered with such art that, the vices of the hearers being diverse, it may be found suitable to them severally, and yet be not diverse from itself; that it pass indeed with one stroke through the midst of passions, but, after the manner of a two-edged sword, cut the swellings of carnal thoughts on either side; so that humility be so preached to the proud that yet fear be not increased in the timid; that confidence be so infused into the timid that yet the unbridled licence of the proud grow not; that solicitude in well doing be so preached to the listless and torpid that yet licence of immoderate action be not increased in the unquiet; that bounds be so set on the unquiet that yet careless torpor be not produced in the listless; that wrath be so extinguished in the impatient that yet negligence grow not in the easy and soft-hearted; that the soft-hearted be so inflamed to zeal that yet fire be not added to the wrathful; that liberality in giving be so infused into the niggardly that yet the reins of profusion be in no wise loosened to the prodigal; that frugality be so preached to the prodigal that yet care to keep perishable things be not increased in the niggardly; that marriage be so praised to the incontinent that yet those who are already continent be not called back to voluptuousness; that virginity of body be so praised to the continent that yet fecundity of the flesh come not to be despised by the married. Good things are so to be preached that ill things be not assisted sideways. The highest good is so to be praised that the lowest be not despaired of. The lowest is so to be cherished that there be no cessation of striving for the highest from the lowest being thought sufficient.
Source: Pastoral Rule (New Advent)