This art of prediction is not attainable any otherwise, than by these three ways; first, it is done by the company of familiar spirits and genii, which are of two sorts; some good and some bad; who tell the gifted person the things of which he informs other people. Secondly, it is performed by the second-sight, which is very various, and differs in most of the possessors, it being but a very little in some, very extensive and constant in others; beginning with some in their infancy, and leaving them before they come to years; happening to others in a middle age, to others again in an old age, that never had it before, and lasting only for a term of years, and now and then for a very short period of time; and in some, intermitting, like fits as it were, of vision, that leave them for a time, and then return to be as strong in them as ever, and it being in a manner hereditary to some families, whose children have it from their infancy, without intermission, to a great old age, and even to the time of their death, which they often foretell before it comes to pass, to a day, nay, even to an hour. Thirdly, it is attained by the diligent study of the lawful part of the art of magic. Before I give the reader an account, as I shall do in three distinct discourses, first, concerning the intercourse which familiar spirits, viz., the good and bad genii, have had and continue to have to a great degree with some select parts of mankind; secondly, concerning the wonderful and almost miraculous power of a second-sight, with which many, beyond all controversy, have been extraordinarily but visibly gifted; and, thirdly, concerning the pitch of perfection to which the magic science has been carried and promoted by some adepts in that mysterious art; I will premise a few particulars about the genii which attended our little Duncan Campbell, and about the second-sight which he had when yet a child, and when we may much more easily believe that the wonders he performed and wrote of, must have been rather brought about by the intervention of such genii and the mediation of such a sight, than that he could have invented such fables concerning them, and compassed such predictions as seem to want their assistance, by the mere dint of a child's capacity.