In short story the bet

Why did the lawyer despise books from which he has learnt so many things during his confinement

 The lawyer despised books and wisdom because he find them worthless, fleeting, illusory, and deceptive, like a mirage. He was convinced that death will wipe off everything from the face of the Earth as though they were no more than mice burrowing under the floor. He believed that one’s posterity, history, and immortal geniuses will burn or freeze together with the earthly globe.