Decentralization is the central value of Ethereum, but is often misinterpreted as supporting isolated individualism. Yet isolation is, paradoxically, a leading cause of centralization. Because most value creation and consumption is social, people need identity and economies have increasing returns to scale, decentralized systems that fail to account for these are quickly taken over by centralized power. Only by embracing the need for collective action through a diverse range of communities can we defend a decentralized society against the threats of authoritarian governments and corporate monopolies. I will discuss three applications of this philosophy of "liberal radicalism". The first is a set of formal funding rules for decentralized funding collective organization I proposed with Vitalik Buteirn and Zoë Hitzig that allow flexible, approximately optimal public goods provision without a central authority. The second is a network-based identity protocol I am working on with Matthew Jackson that uses the community structure of information sharing to improve security without a dominant verifier. The final theme will be the importance of collective organization of users of digital platforms to check the power of those platforms, based on my work with Jaron Lanier. Only such a social view can save decentralization from undermining itself.