These alphabetical Indices will, however, be of little use, unless another, and a very different kind of Index, be arranged in the mind of the reader; an Index explanatory of the principal purposes and contents of the various parts of this essay. It is difficult to analyze the nature of the reluctance with which either a writer or painter takes it upon him to explain the meaning of his own work, even in cases where, without such explanation, it must in a measure remain always disputable: but I am persuaded that this reluctance is, in most instances, carried too far; and that, wherever there really is a serious purpose in a book or a picture, the author does wrong who, either in modesty or vanity (both feelings have their share in producing the dislike of personal interpretation), trusts entirely to the patience and intelligence of the readers or spectators to penetrate into their significance. At all events, I will, as far as possible, spare such trouble with respect to these volumes, by stating here, finally and clearly, both what they intend and what they contain; and this the rather because I have lately noticed, with some surprise, certain reviewers announcing as a discovery, what I thought had lain palpably on the surface of the book, namely, that "if Mr. Ruskin be right, all the architects, and all the architectural teaching of the last three hundred years, must have been wrong." That is indeed precisely the fact; and the very thing I meant to say, which indeed I thought I had said over and over again. I believe the architects of the last three centuries to have been wrong; wrong without exception; wrong totally, and from the foundation. This is exactly the point I have been endeavoring to prove, from the beginning of this work to the end of it. But as it seems not yet to have been stated clearly enough, I will here try to put my entire theorem into an unmistakable form. The various nations who attained eminence in the arts before the time of Christ, each of them, produced forms of architecture which in their various degrees of merit were almost exactly indicative of the degrees of intellectual and moral energy of the nations which originated them; and each reached its greatest perfection at the time when the true energy and prosperity of the people who had invented it were at their culminating point. Many of these various styles of architecture were good, considered in relation to the times and races which gave birth to them; but none were absolutely good or perfect, or fitted for the practice of all future time. The advent of Christianity for the first time rendered possible the full development of the soul of man, and therefore the full development of the arts of man. Christianity gave birth to a new architecture, not only immeasurably superior to all that had preceded it, but demonstrably the best architecture that _can_ exist; perfect in construction and decoration, and fit for the practice of all time.