Being Happy contains all of the extant writing by Epicurus - one of the most influential classical philosophers and the father of Epicureanism. He stresses the therapeutic impact of philosophy, and his belief that happiness comes through understanding how the world works.GREAT IDEAS. Throughout history, some books have changed the world. They have transformed the way we see ourselves - and each other. They have inspired debate, dissent, war and revolution. They have enlightened, outraged, provoked and comforted. They have enriched lives - and destroyed them. Now Penguin brings you the works of the great thinkers, pioneers, radicals and visionaries whose ideas shook civilization and helped make us who we are.