29 And if you examine more closely, how great is the distinction between the married and the unmarried, and among the latter between hermits and those who live together in community, between those who are proficient and advanced in contemplation and those who barely hold on the straight course, between townsfolk again and rustics, between the simple and the designing, between men of business and men of leisure, between those who have met with reverses and those who are prosperous and ignorant of misfortune. For these classes differ sometimes more widely from each other in their desires and passion than in their physical characteristics; or, if you will, in the mixtures and blendings of the elements of which we are composed, and, therefore, to regulate them is no easy task.
Source: Orations (New Advent)