Adam Smith's landmark treatise on the free market paved the way for modern capitalism, arguing that competition is the engine of a productive society, and that self-interest will eventually come to enrich the whole community, as if by an `invisible hand'.

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.