The west front is of great magnificence of material, though a kind of design which seems to have proceeded upon the principle of setting all established architectural styles and customs entirely at defiance. This indeed may be said of the whole church, which is a kind of mixture of Lombard-Romanesque features with some Gothic, and no slight dash of the Renaissance spirit; altogether a most magnificent hybrid, but certainly a hybrid. The doors stand wide open, and from the decaying and desolate court in front of the church we enter into the nave, full of everything that is magnificent in material, and all preserved with jealous care and in admirable order; we look up to the lofty vault which spans the grand width of the nave, and find the groining ribs arched overhead in pure pointed form, and cannot help marvelling how far this one pointed feature harmonizes--I had almost said sanctifies--the whole interior, though in fact, save this one point, there is scarcely a single detail throughout the church which would ever pass muster as really being of Gothic character.
I think it is hardly possible to scan or criticize the architecture of such a building; it is better to follow the guidance of the cicerone, and look at the pictures behind the many altars set around with precious stones, and inclosed within reredoses made of such an infinite variety of marbles, that, with some degree of envy, one thinks how precious such an array would be on this side of the Alps, even if spread through fifty churches.
The nave and aisles are divided from the side chapels and from the transepts by high metal grilles, and the transept is again divided by another screen from the choir: this produces a very singular and unusual effect, and makes the transept appear somewhat like a nave placed at right angles to the choir. All the chapels on either side of the nave communicate with one another, so that the monks are able, without entering the nave, to obtain access to all of them, whilst females are carefully excluded both from the chapels and from the transepts and choir. Except a Perugino in one of the chapels on the north side of the nave, and one picture in the sacristy, there seemed to be no pictures of any very great value; in fact, travellers are asked rather to admire the value of the stones which are used in the altars, and the marbles in the reredoses behind them, than the paintings which they inclose. The groining of the church, enhanced as it is in effect by the way in which it is painted--with a blue ground, powdered very richly with gold stars--conduces more than anything else to the very fine effect of colour which the nave produces; and the beautiful pavements, composed mainly of red and white marbles, laid in elaborate geometrical patterns, increase not a little the general effect. This is an instance of the superiority of decorative painting over pictures as far as improvement of architectural effect is concerned.