The ideas behind Ethereum in the words of its founder, describing a radical vision for more than a digital currency—reinventing organisations, economics, and democracy itself in the age of the internet. At only nineteen years old Vitalik Buterinpublished a visionary paper outlining the ideas behindwhat would become Ethereum. He proposed to take whatBitcoin did for currency – to end the central control ofgovernments and corporations – and apply it to societyas a whole. Now, less than a decade later, Ethereumis the second-most-valuable cryptocurrency and hasopened the gates for the extraordinary new world ofNFT artworks, virtual real estate in the metaverse anddecentralised autonomous organisations. The essays in Proof of Stake reveal Buterin as a lively,creative thinker, relentlessly curious and adventurousin exploring the fascinating social, economic and politicalpossibilities of his invention, and will guide futuregenerations of Ethereum's community of radicalsand builders.