By expression work we mean the endeavour to enforce a lesson, to hasten its assimilation and ensure its retention, by means of some appropriate activity on the part of the learner. This is of course much older than Montessorism, as even our best Sunday school teachers can testify; it can be traced back also beyond Froebel. Its origin is, surely, lost in the prehistoric ages of pedagogy. But it was Froebel in the nineteenth century who first claimed for this factor the importance which it holds in modern education. Yet if we study Dante’s _Purgatorio_ we shall find expression work on every terrace of the Mountain, from the humble, stooping march of the cornice of Pride to the significant exclamations wherewith the once Lustful, on the uppermost terrace, punctuate the chanting of their hymn, _Summae Deus clementiae_. Purgatory is not for Dante, as for Aquinas, merely penal suffering—“something to be borne.” It must be (as Mr. Wicksteed observes)[210] something active—“something to be and to do”—somewhat more definite, more specific, more varied than mere suffering is needed for the building up of the new life which is to be at home once more in Eden. As in the Montessori school, so in these mystic “cloisters” the learners are led to concentrate and focus on a single task a number of faculties and senses: eye, ear, voice, memory, attitude, gesture and movement all conspire to enforce the lesson. And this variety of expression work is rendered effective by an abundant supply of didactic material, an apparatus as carefully and scientifically thought out as that of Italy’s latest educational leader. One need only instance the famous wall-sculptures[211] and the inlaid pavement[212] of the Terrace of Pride, the description of which forms one of the loveliest passages in this most beautiful poem.