James Mackcoull received a very limited education, and could just read and write. At school he was frequently detected purloining the playthings of other boys; and at a very tender age he robbed a poor man who sold cats'-meat through the streets. The young villain saw the vender of offal put his money, as he received it, into a bag which hung on the handle of his barrow, and, watching his opportunity, when the owner's back was turned, he cut the cord, and carried off the booty. Emboldened by success, he ventured again and again, and soon associated himself with gangs who were known to infest the entrances to theatres and places of amusement. The father, ignorant of the vicious habits of the son, bound him apprentice to a leather-stainer, in Clerkenwell; but James, encouraged by his mother, adhered to his former comrades, and soon gave occasion to his master to discharge him. He now became a notorious thief, and, by shifting his quarters, continued to elude detection; but, having been engaged with another in snatching the seals of a gentleman's watch in St. James's Park, they were pursued. Mackcoull's companion was apprehended; and he only escaped detection by going at night on board the Tender, at Tower Hill, and entering as a volunteer. For two years he remained on board the Apollo frigate, in the character of an officer's servant, and afterwards on board the Centurion, in the same capacity. In the absence of temptation even a rogue may be honest; and Mackcoull acquired so good a character in the navy, that he was in a few years appointed purser's steward, and in the course of nine years saved a considerable sum of money. In 1785 he returned to London, where, in a short time, he dissipated all his earnings in the society of the dissolute and abandoned, and to repair his finances had recourse to his former habits of dishonesty. He soon eclipsed all his companions in iniquity, and shone pre-eminent as a pugilist, horse-racer, cock-fighter, gambler, swindler, and pickpocket. To carry on his depredations with success he assumed various characters, and succeeded in all. Not even the sanctuary of religion was free from his desperate villany; for he frequently went there to pick pockets, and on one occasion deprived the preacher of his watch, on his way from the pulpit. The knowledge and acuteness he displayed, as well as the successful manner in which he avoided discovery, procured him among his associates the appellation of "The Heathen Philosopher."