Latinism in which soul is adjective : mother nurture, mother who vivifies. In classical Rome it was said of the goddess Ceres, Cibeles or even Venus. In the Middle Ages and later it has been said of the Italian university of Bologna (alma mater studiorum), the oldest in the West, and by extension of every university. The most common current use of the locution substantializes the soul by pointing to the person who drives or has the full force of a project or activity.
