It is now more than forty years since it was remarked by Jeffrey, in his _Review_, that metaphysical science was decidedly on the decline in Scotland. Dugald Stewart, though in a delicate state of health at the time, was in the full vigour of his faculties, and had still eighteen years of life before him; Thomas Brown had just been appointed his assistant and successor in the Moral Philosophy Chair of the University of Edinburgh; and the _élite_ of the Scottish capital were flocking in crowds to his class-room, captivated by the eloquence and ingenuity of his singularly vigorous and original lectures. Even fifteen years subsequent, Dr. Welsh could state, in the Life of his friend, that the reception of his work on the _Philosophy of the Human Mind_ had been 'favourable to a degree of which, in metaphysical writings, there was no parallel.' It has been recorded as a very remarkable circumstance, that the _Essay_ of Locke--produced at a period when the mind of Europe first awoke to general activity in the metaphysical province--passed through seven editions in the comparatively brief space of fourteen years. The _Lectures_ of Dr. Brown passed through exactly seven editions in _twelve_ years, and this at a time when, according to Jeffrey, that science of mind of which they treated was in a state of gradual decay. The critic was, however, in the right. The genius of Brown had imparted to his brilliant posthumous work an interest which could scarce be regarded as attaching to the subject of it; and in a few years after--from about the year 1835 till after the disruption of the Scottish Church--metaphysical science had sunk, not in Scotland only, but all over Britain, to its lowest ebb. A few retired scholars continued to prosecute their researches in the province of mind; but scarce any interest attached to their writings, and not a bookseller could be found hardy enough to publish at his own risk a metaphysical work. We are old enough to remember a time, contemporaneous with the latter days of Brown, when young students, in their course of preparation for the learned professions, especially for the Church, used to be ever recurring in conversation to the staple metaphysical questions,--occasionally, no doubt, much in the style of Jack Lizard in the _Guardian_, who comforted his mother, when the worthy lady was so unlucky as to scald her hand with the boiling tea-kettle, by assuring her there was no such thing as heat, but which at least served to show that this branch of liberal education fully occupied the mind of the individuals ostensibly engaged in mastering it; and we remember a subsequent time, when students--some of them very clever ones--seemed never to have thought on these questions at all, and remained silent in conversation when they chanced to be mooted by the men of an earlier generation. During, however, the last ten years, mainly through the revival of a taste for metaphysical inquiry in France