life to this object; earnestly desiring to ascertain, and be able to teach, the truth respecting art; and also knowing that this truth was, by time and labour, definitely ascertainable.

It is an idea too frequently entertained, by persons who are not much interested in art, that there are no laws of right or wrong concerning it; and that the best art is that which pleases most widely. Hence the constant allegation of "dogmatism" against any one who states unhesitatingly either preference or principle, respecting pictures. There are, however, laws of truth and right in painting, just as fixed as those of harmony in music, or of affinity in chemistry. Those laws are

perfectly ascertainable by labour, and ascertainable no otherwise. It is as ridiculous for any one to speak positively about painting who has not given a great part of his life to its study, as it would be for a person who had never studied chemistry to give a lecture on affinities of elements; but it is also as ridiculous for a person to speak hesitatingly about laws of painting who has conscientiously given his time to their ascertainment, as it would be for Mr. Faraday to announce in a dubious manner that iron had an affinity for oxygen, and to put the question to the vote of his audience whether it had or not. Of course there are many things, in all stages of knowledge, which cannot be dogmatically stated; and it will be found, by any candid reader, either of what I have before written, or of this book that, in many cases, I am not dogmatic. The phrase, "I think so," or, "it seems so to me," will be met with continually; and I pray the reader to believe

that I use such expression always in seriousness, never as matter of form.

It may perhaps be thought that, considering the not very elaborate structure of the following volumes, they might have been finished sooner. But it will be found, on reflection, that the ranges of inquiry engaged in demanded, even for their slight investigation, time and pains which are quite unrepresented in the result. It often required a week or two's hard walking to determine some geological problem, now dismissed in an unnoticed sentence; and it constantly needed examination and thought, prolonged during many days in the picture gallery, to form opinions which the reader may suppose to be dictated by caprice, and will hear only to dispute.

A more serious disadvantage, resulting from the necessary breadth of subject, was the chance of making mistakes in minor and accessory points. For the labour of a critic who sincerely desires to be just, extends into more fields than it is possible for any single hand to furrow straightly. He has to take some note of many physical sciences; of optics, geometry, geology, botany, and anatomy; he must acquaint himself with the works of all great artists, and with the temper and history of the times in which they lived; he must be a fair metaphysician, and a careful observer of the phenomena of natural scenery. It is not possible to extend the range of work thus widely, without running the chance of occasionally making mistakes; and if I carefully guarded against that chance, I should be compelled both to shorten my powers of usefulness in many directions, and to lose much time over what work I

undertook. All that I can secure, therefore, is rightness in main points and main tendencies; for it is perfectly possible to protect oneself against small errors, and yet to make great and final error in the sum of work: on the other hand, it is equally possible to fall into many small errors, and yet be right in tendency all the while, and entirely right in the end. In this respect, some men may be compared to careful travellers, who neither stumble at stones, nor slip in sloughs, but have, from the beginning of their journey to its close, chosen the wrong road; and others to those who, however slipping or stumbling at the wayside, have yet their eyes fixed on the true gate and goal (stumbling, perhaps, even the more because they have), and will not fail of reaching them. Such are assuredly the safer guides: he who follows them may avoid their slips, and be their companion in attainment.

Although, therefore, it is not possible but that, in the discussion of so many subjects as are necessarily introduced in the following pages, here and there a chance should arise of minor mistake or misconception, the reader need not be disturbed by the detection of any such. He will find always that they do not affect the matter mainly in hand.

I refer especially in these remarks to the chapters on Classical and Medieval Landscape. It is certain, that in many respects, the views there stated must be inaccurate or incomplete; for how should it be otherwise when the subject is one whose proper discussion would require knowledge of the entire history of two great ages of the world? But I am well assured that the suggestions

in those chapters are useful; and that even if, after farther study of the subject, the reader should find cause to differ with me in this or the other speciality, he will yet thank me for helping him to a certain length in the investigation, and confess, perhaps, that he could not at last have been right, if I had not first ventured to be wrong.

And of one thing he may be certified, that any error I fall into will not be in an illogical deduction: I may mistake the meaning of a symbol, or the angle of a rockcleavage, but not draw an inconsequent conclusion. I state this, because it has often been said that I am not logical, by persons who do not so much as know what logic means. Next to imagination, the power of perceiving logical relation is one of the rarest among men: certainly, of those with whom I have conversed, I have found always ten who had deep feeling, quick wit, or extended knowledge, for one who could set down a syllogism without a flaw; and for ten who could set down a syllogism, only one who could entirely understand that a square has four sides. Even as I am sending these sheets to press, a work is put into my hand, written to prove (I would, from the depth of my heart, it could prove) that there was no ground for what I said in the Stones of Venice respecting the logical probability of the continuity of evil. It seems learned, temperate, thoughtful, everything in feeling and aim that a book should be, and yet it begins with this sentence :

"The question cited in our preface, 'Why not infinite good out of infinite evil?' must be taken to imply—for it else can have no weight,—that in order to the production of infinite good, the existence of infinite evil is indispensable."

So, if I had said that there was no reason why honey should not be sucked out of a rock, and oil out of a flinty rock, the writer would have told me this sentence must be taken to imply—for it else could have no weight,—that in order to the production of honey, the existence of rocks is indispensable. No less intense and marvellous are the logical errors into which our best writers are continually falling, owing to the notion that laws of logic will help them better than common sense. Whereas any man who can reason at all, does it instinctively, and takes leaps over intermediate syllogisms by the score, yet never misses his footing at the end of the leap; but he who cannot instinctively argue, might as well, with the gout in both feet, try to follow a chamois hunter by the help of crutches, as to follow, by the help of syllogism, a person who has the right use of his reason. I should not, however, have thought it necessary to allude to this common charge against my writings, but that it happens to confirm some views I have long entertained, and which the reader will find glanced at in their proper place, respecting the necessity of a more practically logical education for our youth. Of other various charges I need take no note, because they are always answered the one by the other. The complaint made against me to-day for being narrow and exclusive, is met to-morrow by indignation that I should admire schools whose characters cannot be reconciled; and the assertion of one critic, that I am always contradicting myself, is balanced by the vexation of another, at my ten years' obstinacies in error.

I once intended the illustrations to these volumes to be more numerous and elaborate, but the art of photography