The most permanent influence exerted by Comenius was in practical educational work. Few men since his days have had a greater influence though, for the greater part of the eighteenth century and the early part of the nineteenth, there was little recognition of his relationship to the current advance in educational thought and practice. The practical educational influence of Comenius was threefold. He was first a teacher and an organizer of schools, not only among his own people, but later in Sweden, and to a slight extent in Holland. In his "Didactica Magna" (Great Didactic), he outlined a system of schools that is the exact counterpart of the existing American system of kindergarten, elementary school, secondary school, college, and university.