As they now stand, Mantes is the oldest.  While conscientiously trying to keep as far away as we can from technique, about which we know nothing and should care if possible still less if only ignorance would help us to feel what we do not understand, still the conscience is happier if it gains a little conviction, founded on what it thinks a fact.  Even theologians—­even the great theologians of the thirteenth century—­even Saint Thomas Aquinas himself—­did not trust to faith alone, or assume the existence of God; and what Saint Thomas found necessary in philosophy may also be a sure source of consolation in the difficulties of art.  The church at Mantes is a very early fact in Gothic art; indeed, it is one of the earliest; for our purposes it will serve as the very earliest of pure Gothic churches, after the Transition, and this we are told to study in its windows.

Before one can get near enough fairly to mark the details of the facade, one sees the great rose window which fills a space nearly twenty-seven feet in width.  Gothic fanatics commonly reckon the great rose windows of the thirteenth century as the most beautiful creation of their art, among the details of ornament; and this particular rose is the direct parent of that at Chartres, which is classic like the Parthenon, while both of them served as models or guides for that at Paris which dates from 1220, those in the north and south transepts at Rheims, about 1230, and so on, from parent to child, till the rose faded forever.  No doubt there were Romanesque roses before 1200, and we shall see them, but this rose of Mantes is the first Gothic rose of great dimensions, and that from which the others grew; in its simplicity, its honesty, its large liberality of plan, it is also one of the best, if M. Viollet-le-Duc is a true guide; but you will see a hundred roses, first or last, and can choose as you would among the flowers.

More interesting than even the great rose of the portal is the remark that the same rose-motive is carried round the church throughout its entire system of fenestration.  As one follows it, on the outside, one sees that all the windows are constructed on the same rose-scheme; but the most curious arrangement is in the choir inside the church.  You look up to each of the windows through a sort of tunnel or telescope:  an arch enlarging outwards, the roses at the end resembling “oeil-de-boeufs,” “oculi.”  So curious is this arrangement that Viollet-le-Duc has shown it, under the head “Triforium,” in drawings and sections which any one can study who likes; its interest to us is that this arrangement in the choir was probably the experiment which proved a failure in Notre Dame at Paris, and led to the tearing-out the old windows and substituting those which still stand.  Perhaps the rose did not give enough light, although the church at Mantes seems well lighted, and even at Paris the rose windows remain in the transepts and in one bay of the nave.