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.

Plato's retelling of the discourses between Socrates and his friends on such subjects as love and desire, truth and illusion, spiritual transcendence and the qualities of a good ruler, profoundly affected the ways in which we view human relationships, society and leadership - and shaped the whole tradition of Western philosophy.