Mind and Matter are two great realities. When people are informed that all thought is explained by vibrations and "vibratiuncles" of the brain, and that what they consider their arms and legs are not arms and legs but ideas, then, says the lecturer, they will pardonably identify Philosophy with Lunacy. "Bishop Berkeley destroyed this world in one octavo volume; and nothing remained after his time but Mind; which experienced a similar fate at the hand of Mr. Hume in 1737.... But is there any one out of Bedlam who _doubts_ of the existence of matter? who doubts of his own personal identity? or of his consciousness? or of the general credibility of memory?" From this rough-and-ready delimitation of the area within which Moral Philosophy must work, if it is to escape the reproach of insanity, the lecturer goes on, as becomes a divine, to champion his study against the reproach of tending to Atheism. He groups all our senses, faculties, and impulses together, and says: "All these things Moral Philosophy observes, and, observing, adores the Being from whence they proceed." Having thus defined his subject, the lecturer goes on, in his second and third lectures, to trace the history of Moral Philosophy, from Pythagoras to Mrs. Trimmer. Plato is praised for beauty of style, and blamed for mistiness of doctrine. Aristotle is contrasted, greatly to his disadvantage, with Bacon. "Volumes of Aristotelian philosophy have been written which, if piled one upon another, would have equalled the Tower of Babel in Height, and far exceeded it in Confusion." But to Bacon "we are indebted for an almost daily extension of our knowledge of the laws of nature in the outward world; and the same modest and cautious spirit of enquiry, extended to Moral Philosophy, will probably give us clear, intelligible ideas of our spiritual nature." The remaining lectures of this course are those which suffered most severely from the flames, and are indeed in so fragmentary a condition as to render any close criticism of them impossible. But enough has been quoted to show that Sydney Smith, so far as he was in any sense concerned with philosophy, was a sworn foe to mysticism and ideality, and a worshipper of Baconian common-sense even in the sphere of mind and soul. He was never tired of poking fun at his philosophical friends in Edinburgh. When sending some Scotch grouse to Lady Holland, he said--"I take the liberty to send you two brace of grouse--curious, because killed by a Scotch metaphysician: in other and better language, they are mere ideas, shot by other ideas, out of a pure intellectual notion called a gun." In another letter to the same correspondent he says--"I hope you are reading Mr. Stewart's book, and are far gone in the Philosophy of Mind--a science, as he repeatedly tells us, still in its infancy. I propose, myself, to wait till it comes to years of discretion." To his friend Jeffrey he wrote in 1804:--