A learned friend, and an observer of men of science, has supplied me with a remark highly deserving notice. It is an observation that will generally hold good, that the most important systems of theory, however late they may be published, have been formed at a very early period of life. This important observation may be verified by some striking facts. A most curious one will be found in Lord BACON'S letter to Father Fulgentio, where he gives an account of his projecting his philosophy thirty years before, during his youth. MILTON from early youth mused on the composition of an epic. DE THOU has himself told us, that from his tender youth his mind was full of the idea of composing a history of his own times; and his whole life was passed in preparation, and in a continued accession of materials for a future period. From the age of twenty, MONTESQUIEU was preparing the materials of _L'Esprit des Loix_, by extracts from the immense volumes of civil law. TILLEMONT'S vast labours were traced out in his mind at the early age of nineteen, on reading Baronius; and some of the finest passages in RACINE'S tragedies were composed while a pupil, wandering in the woods of the Port-Royal. So true is it that the seeds of many of our great literary and scientific works were lying, for many years antecedent to their being given to the world, in a latent state of germination.[A] [Footnote A: I need not to be reminded, that I am not worth mentioning among the illustrious men who have long formed the familiar subjects of my delightful researches. But with the middling as well as with the great, the same habits must operate. Early in life, I was struck by the inductive philosophy of Bacon, and sought after a Moral Experimental Philosophy; and I had then in my mind an observation of Lord Bolingbroke's, for I see I quoted it thirty years ago, that "Abstract or general propositions, though never so true, appear obscure or doubtful to us very often till they are explained by examples." So far back as in 1793 I published "A Dissertation on Anecdotes," with the simplicity of a young votary; there I deduced results, and threw out a magnificent project not very practicable. From that time to the hour I am now writing, my metal has been running in this mould, and I still keep casting philosophy into anecdotes, and anecdotes into philosophy. As I began I fear I shall end.]