About this time also a book came in his way, which seems to have made a revolution in his mind. This was Locke's famous "Essay on the Human Understanding," a copy of which was brought to Drew's master's to be bound. The young shoemaker had read nothing of the kind. It opened to his mind a world of thought that was new to his experience, yet one that seemed familiar on account of his natural aptitude for such studies. He read the luminous pages of the great philosopher with the utmost avidity. Henceforth reading became with him an intense appetite. Nothing came much amiss, but such books as led him into the ample domains of philosophy and religion afforded the greatest delight. He says, "This book (Locke's Essay) set all my soul to think.... It gave the first metaphysical turn to my mind, and I cultivated the little knowledge of writing which I had acquired in order to put down my reflections. It awakened me from my stupor, and induced me to form a resolution to abandon the grovelling views which I had been accustomed to entertain." For two years after the change we have noticed Drew continued working industriously at his trade, and filling up all his spare moments by reading such books as came to the shop to be bound, or any others he could borrow from friends. Attracted by one science after another, and finding, as most eager minds do, a charm in each, he finally settled to metaphysics, because, as he sometimes shrewdly observed, among other recommendations it has this, that it requires fewer books than other branches of study, and may be followed at the least expense. "It appeared to be a thorny path; but I determined nevertheless to enter and begin to tread it," he remarks; and adds, "To metaphysics I then applied myself, and became what the world and Dr. Clarke call a METAPHYSICIAN."