Froude's Disease does not appear to have ever been studied by the psychologists, nor, indeed, is it to be considered as a separate pathological entity. Every one makes mistakes "out of carelessness," "through inadvertence," and in many other ways. What is abnormal is to make many mistakes, to be always making them, in spite of the most persevering efforts to be exact. Probably this phenomenon is connected with weakness of the attention and excessive activity of the involuntary (or subconscious) imagination which the will of the patient, lacking strength and stability, is unable sufficiently to control. The involuntary imagination intrudes upon intellectual operations only to vitiate them; its part is to fill up the gaps of memory by conjecture, to magnify and attenuate realities, and to confuse them with the products of pure invention. Most children distort everything by inexactitude of this kind, and it is only after a hard struggle that they ever attain to a scrupulous accuracy--that is, learn to master their imagination. Many men remain children, in this respect, the whole of their lives. But, let the psychological causes of Froude's Disease be what they may, another point claims our attention. The man of the sanest and best-balanced mind is liable to bungle the simplest kinds of critical work if he does not allow them the necessary time. In these matters precipitancy is the source of innumerable errors. It is rightly said that patience is the cardinal virtue of the scholar. Do not work too fast, act as if there were always something to be gained by waiting, leave work undone rather than spoil it: these are maxims easy enough to pronounce, but not to be followed in practice by any but persons of calm temperament. There are nervous, excitable persons, who are always in a hurry to get to the end, always seeking variety in their occupations, and always anxious to dazzle and astonish: these may possibly find honourable employment in other careers; but if they embrace erudition, they are doomed to pile up a mass of provisional work, which is likely to do more harm than good, and is sure in the long run to cause them many a vexation. The true scholar is cool, reserved, circumspect. In the midst of the turmoil of life, which flows past him like a torrent, he never hurries. Why should he hurry? The important thing is, that the work he does should be solid, definitive, imperishable. Better "spend weeks polishing a masterpiece of a score of pages" in order to convince two or three among the scholars of Europe that a particular charter is spurious, or take ten years to construct the best possible text of a corrupt document, than give to the press in the same interval volumes of moderately accurate _anecdota_ which future scholars will some day have to put through the mill again from beginning to end.