Industrialization in the eighteenth and nineteenth centuries enlarged the possible roles of universities in three major respects. The range of topics that could be offered expanded as technical and commercial subjects joined the arts curriculum and the traditional learned professions of law, medicine, and theology. In addition, shifts in societal composition as a result of industrialization changed the mix of the pool from which students could be drawn. As the rural sector shrank and overall population increased, a much larger group of students from urban backgrounds became available, some of whom derived from the new middle classes and others from the industrial working class. Finally, as industrialization increased the need for literacy and numeracy throughout society, the demand for university-educated teachers grew.